Pruning Intensity Research Articles

Growth performance of wheat varieties under different pruning intensities of Dalbargia sissoo based Agri-silviculture system

A field experiment was carried out at Dusty Acre Research Farm, Department of Forestry, JNKVV, Jabalpur to assess the growth performance of wheat varieties in 13 year old Dalbergia sissoo plantation. Maximum grain yield of wheat was recorded when grown under open condition (27.20 q ha-1). Among different pruning intensities, significantly maximum grain yield was recorded under 75% pruning (24.4 q ha-1) which inturn was significantly superior to 50% pruning (21.27 q ha-1) and 25% pruning (19.47 q ha-1). No pruning recorded significantly lowest grain yield (17.74 q ha-1). The percent reduction in grain yield under no pruning 25%, 50% and 75%. Pruning as compared to open condition was 34.75%, 28.41%, 21.80% and 10.29% respectively. Wheat varieties showed no significant effect on straw yield, however variety Sujata recorded higher straw yield as compared to variety MP 3173 and MP 3288. Different wheat varieties showed significant effect on harvest index. Variety MP 3288 recorded significantly higher harvest index (34.96) followed by MP 3288 (33.90). Variety Sujata recorded lowest harvest index (32.51).

Estimation of tomato yield gaps for greenhouse in Uruguay

Yield gap analysis is a powerful method to explore gap’s breadth between potential yields, attainable and those realized in farmers’ fields, identifying constraints to production and assess opportunities to yield increase. We assessed yields and yield components across two seasons, in 110 greenhouse tomato (Solanum lycopersicum) crops during 2014/15 and 2015/16 in the south region of Uruguay, and compared them with potential and attainable yield. Potential yield was calculated with a simulation model based on photosynthetic active radiation (PAR) and light use efficiency, and TOMSIM to estimate assimilate partition and fruit yield. Since yield was primarily determined by cumulative PAR intercepted, a boundary function was fitted to estimate attainable yield as a function of cumulative PAR intercepted. Our study quantified a yield gap of 10.7 kg m−2 or 44 % relative to potential. Overall gap was divided into three components: difference between actual and attainable (45 % of total gap), attainable and potential with actual greenhouse PAR transmissivity (29 % of total gap) and between potential with actual transmissivity and potential with 70 % of greenhouse transmissivity (26 % of total gap). For long summer and short spring/summer crops the greatest impact in yield could be obtained by increasing leaf area index by reducing plant lowering operations and leaf pruning intensity, and by increasing plant density. For autumn crops, yield could be improved by earlier planting, reducing leaf pruning intensity after harvest beginning, and increasing greenhouse transmissivity by more frequent plastic cover renewal and removing roofs’ shading screens and whitening.

Effects of pruning intensity on nonstructural carbohydrates of Populus alba × P. talassica in the arid desert region of Northwest China

Although pruning is important to obtain high-quality, large-diameter timber, the effects of pruning on nonstructural carbohydrates (NSC) in aboveground organs of many timber species are not well understood. Three intensities of pruning (none, moderate and severe) were tested on poplars (Populus alba × P. talassica) in the arid desert region of northwest China to compare the concentrations of soluble sugar (SS), starch (ST) and total nonstructural carbohydrate (TNC) in leaves, branches and trunks during the growing season. The concentration of NSC components after different pruning intensities varied similarly in seasonal patterns, increasing slowly at the beginning of the growing season, continuously declining in the middle, then gradually recovering by the end of the growing season. The monthly mean NSC concentration in poplar differed significantly among the three pruning intensities (p branch > trunk, while the order of ST concentration was trunk > leaf > branch, which was related to functional differences of plant organs. The annual average growth in height of unpruned, moderately pruned, and severely pruned poplars was 0.21 ± 0.06, 0.45 ± 0.09 and 0.24 ± 0.05 m, respectively, and the annual average growth in DBH were 0.92 ± 0.04, 1.27 ± 0.06 and 1.02 ± 0.05 cm, respectively. Our results demonstrate that moderate pruning may effectively increase the annual growth in tree height and DBH while avoiding damage caused by excessive pruning to the tree body. Therefore, moderate pruning may increase the NSC storage and improve the growth of timber species.

Pruning intensity influences growth, flower and fruit development of Moringa oleifera Lam. under sub-optimal growing conditions in Gauteng, South Africa

Moringa oleifera Lam. is becoming increasingly popular as an industrial crop due to its multitude of useful attributes as a water purifier, nutritional supplement and biofuel feedstock. Horticultural practices such as pruning that encourage improved production of M. oleifera in terms of flowers and fruits have been given little attention especially in sub-Sahara Africa. This study therefore aimed to establish an ideal pruning intensity level on ±5 year old M. oleifera trees. A trial was conducted at the University of Pretoria Experimental Farm of the Hillcrest Campus on trees of an established orchard with four treatments namely severe (1 m), moderate (2 m), light (3 m) pruning above the ground level (pollarding), and no pruning (control). These were applied once in September for two consecutive years. Individual inflorescences from each treatment were tagged during floral initiation and monitored throughout until fruiting stage. Records for Leaf Area Index (LAI), fresh and dry biomass, chlorophyll content, as well as tree stem circumference were taken over a period time at around 81, 98 and 124 days after pruning (DAP). Results showed that light pruning (3 m from the ground) resulted in the highest quantity of flower buds at 124 DAP, and of flowers at 98 DAP in both years. In addition, moderate pruning (2 m from the ground) increased flower number on trees at 124 DAP. Highest quantity of fruits were recorded from the moderate pruning treatment. Measurements done on total leaf area, fresh and dry biomass showed that although plants pruned at 1 m above the ground (severe pruning) received better initial penetration of light into the plant canopy, not enough plant vigor could out-perform plants pruned at 2 m above the ground level. Moderately pruned trees also recorded a substantial increase in stem circumference in comparison to the control and lightly pruned trees at 124 DAP in the first year. Moderate pruning promoted significantly higher total chlorophyll accumulations in mature leaves. Although the onset of low temperatures in both years may have led to increased flower abortion resulting in lower fruit numbers across treatments, results suggest that pruning a M. oleifera tree at 3 m (light) and 2 m (moderate) above ground level under sub-optimal growing conditions in Gauteng, South Africa once a year, will result in maximum flower and fruit harvest. The moderately, but also the severely pruned trees produced more than double the amount of fresh biomass in comparison to the control and lightly pruned trees. This study therefore concludes that M. oleifera crop production for the sole purpose of fruit production may not be optimal in Pretoria, Gauteng, however, leaf production is promising due to the higher plant biomass recorded with the moderate pruning treatment.

BUNCH NUMBER AND ANTIOXIDANT ACTIVITY IN ‘SAHEBI’ AND ‘HALAGHO’ GRAPES AFFECTED BY PRUNING INTENSITY AND CANE LENGTH

Pruning methods can primarily affect grape production at various levels. Of the commonly affected features by pruning, the number of bunches has known to have a significant effect on the relation between the functions of assimilate sources and sinks. Further, fruitfulness can significantly be negatively influenced by shading. In this study, we aim to study the impact of 4, 6 and 8 buds per cane with pruning intensity as light, moderate and severely pruned and their interaction in the course two consecutive years, 2017 and 2018 in ‘Sahebi’ and ‘Halagho’ (both seeded red table grape cultivars). In 2018, lightly pruned ‘Halagho’ and having 8 buds per cane increased number of bunches by 54.00, which had the highest value. Results showed that there is apical buds bear more fruit by comparison to the buds with vegetative nature, 1 to 4 first buds. Based upon the outcomes of this study, it could be concluded that due to the stresses imposed by the pruning of the vines, therefore, the chemical compounds increases in order alleviate the negative aftermaths . In 2018, whole berry antioxidant activity in both cultivars was significantly lessened, and this decline was higher in ‘Saahebi’. The number of bunches was increased by increasing cane length or bud load/cane. Overall, the pruning program has an impactful role in bunch number as well as antioxidant activity and in the long-run on accumulated reserves, which makes choosing and applying a specific pruning method undeniably important. Thus, emphasize the importance of further research in this field.

Chemical root pruning improves quality and nutrient uptake of Cape Gooseberry (Physalis peruviana) seedlings

Cape gooseberry is an annual crop in temperate regions, and it is yearly planted in seed trays for initial development, and outplanted to the field for fruit production. Although, a matted and spiraled root morphology, as a consequence of seed trays/containers, may negatively interfere the outplanted seedling performance due to such impaired attributes. Thus, the objective of this study was: (1) to determine the effect of chemical root pruning on quality of cape gooseberry seedlings (2) to determine whether copper hydroxide or copper oxide, and the appropriate rates that are the most effective to enhance seedling quality. To do so, the cells of seed trays were painted internally with a mix of latex ink and copper hydroxide or copper oxide at the rates of 0, 12, 24, 36, and 48 g.L−1 of Cu (equivalent of metallic copper), for the seedlings of cape gooseberry to grow throughout 87 and 105 days after sowing (DAS). Both copper compounds promoted root pruning accordingly to the rate. For the seedlings grown throughout 87 days in the seed trays, the effect of root pruning intensity caused by copper hydroxide induced the seedlings to have a balanced shoot growth, an improved root system morphology, and a better nutritional status that was achieved with the concentration of 24 g.L-1 of Cu. The same was found for the seedlings grown throughout 105 days in the seed trays, with copper hydroxide at the concentration of 48 g.L-1 of Cu. These results suggest that chemical root pruning of seedlings using copper hydroxide improves root morphology and increases the nutrient uptake capacity.

Pruning promotes the formation of an insufficient number of cavities for hollow-dependent birds in Iberian Holm-oak dehesas

Holm oak Quercus ilex dehesas cover large areas in the Mediterranean region, and constitute a paradigm of well preserved low-intensity agro-ecosystem supporting a high number of bird species. The canopy of holm oak trees is periodically pruned, but the role of pruning in the process of tree-hollow formation remains unstudied. Here I investigate the occurrence of tree-hollows in relation to tree characteristics (vitality, trunk diameter and fork height), infection by drilling Coleoptera and pruning intensity, and assess likely origin, use and suitability of hollows for non-excavator birds in dehesas of Spain. 26.3% of all sampled oaks had at least one hollow, and the number of pruning cuts predicted the occurrence of hollows. 97.0% of hollows were situated on pruning cuts suggesting that pruning may have favored decay cavity formation in Iberian dehesas. 43.6% of hollows were estimated suitable to hold the nest of a small-sized cavity-nesting bird, but only 11.9% might have potentially held the nest of a medium-sized cavity-nesting bird, rendering estimated 3.9 and 1.1 potential cavities/ha, respectively. The low densities of suitable hollows would point toward a lack of nest-sites which might limit cavity-nesting birds in holm oak dehesas. Future conservation actions targeting in protection of old and dead holm oak trees instead of selective removal, together with land-scale measurements of enhancement of riverine forests stands may enrich and ensure the persistence of cavity-using species in Iberian dehesas.

Long-term taper and growth reductions following pruning intensity treatments in giant sequoia (Sequoiadendron giganteum)

A high degree of stem taper limits the potential value of giant sequoia (Sequoiadendron giganteum (Lindl.) J. Buchholz) when grown for timber. I measured the effects of pruning to different height targets (0, 2.0, 3.5, and 5.5 m), resulting in the removal of 25%–85% of crown length, on the growth of 360 S. giganteum trees over 17 years. Height growth and growth of diameter at breast height were both negatively related to pruning intensity to a similar degree. Within the 17 years following pruning, repeated measurements of stem growth at different heights above the ground revealed that radial stem growth reductions were localized on the stems from which branches were removed. The higher up that trees were pruned, the more that stem radial growth was reduced compared with control trees, with the greatest reductions occurring at stem bases. The effects of pruning decreased over time, but there were still significant differences after 17 years. Girard form class was only influenced by the most intense pruning at a stem height of 5.5 m. A benefit of pruning was reduced taper, but this came at the cost of reduced stem growth. Pruning in S. giganteum must be done carefully with respect to its timing, intensity, and interactions with other management treatments on young stands.

MORPHOMETRY OF TRACHEIDS OF Pinus taeda L. FROM A PRUNING TEST IN NE ARGENTINA.

The northeast region of Argentina is characterized by fast-growing forest plantations, Pinus taeda among them. The objective of this study was to evaluate the influence of pruning and stand structure on the morphometric characteristics of tree tracheids. We evaluated 18 trees of 16 years old, from a silvicultural stand essay, with 1660 plants/ha as initial density, without thinning, three pruning treatments 0%, 50% and 70% removal of the green crown belong to the dominant, codominant and suppressed strata. Tree slices were taken at 1.3 m height, the conditioned samples were observed and measured with a microscope with digital camera. The data was analyzed using mixed linear models. Pruning did not have effect on the width and length of tracheids, but it affected to the cell wall thickness, which decreased with increasing pruning intensity. While the social position (stratum) had significant influences on the length of tracheids, given greater for individual in dominant stratum, followed by codominant and suppressed stratum. The cell wall width and thickness were not affected by the stratum. Regardless of the social position in the stand, the tracheid’s length showed an increasing pattern from pith to bark with the lower values near to the pith.

New aboveground biomass and nitrogen yield in different ages of gliricidia (Gliricidia sepium Jacq.) trees under different pruning intensities in moist semi-deciduous forest zone of Ghana

Pruning of woody perennials is extensively practiced among farmers in agroforestry. We investigated different pruning frequencies on new aboveground biomass, nitrogen concentration and nitrogen yield on gliricidia (Gliricidia sepium) trees of different ages. Two sites were selected in Ghana where gliricidia trees were intercropped in cocoa agroforestry system. One site had young (within 5 years) trees whilst the other had old (above 10 years) trees. A total of 15 gliricidia trees were selected from each site. Five pruning regimes (2, 4, 6, 8 and 10 months) was assigned to each tree and replicated 3 times. The result showed that shoot biomass among the different pruning regimes varied significantly (P < 0.05) in both age groups, with more biomass found in the shoot axes than in leaves as pruning delayed. Maximum biomass in old trees was 67.15 kg/tree at 8 months compared to 49.37 kg/tree at 10 months in young trees. N concentration pattern differed from the biomass, as %N were significantly lower (P < 0.05) as pruning delayed in both age groups. At 4 months, young trees had 57 kg N ha−1 compared to 64 kg N ha−1 at 8 months in old trees. In conclusion, pruning regimes in gliricidia should be guided by the age of the trees. Hence, it would be theoretically enough to prune young trees at 4 months and old trees at 8 months to meet the N need (58–80 kg ha−1) of cocoa to diminish external N-fertilizer needs.

Effect of pruning intensity on soil moisture and water use efficiency in jujube (Ziziphus jujube Mill.) plantations in the hilly Loess Plateau Region, China

Jujube (Ziziphus jujube Mill.) is a traditional economic forest crop and is widely cultivated in hilly areas of the Loess Plateau, China. However, soil desiccation was discovered in jujube plantations. Pruning is recognized as a water-saving method that can reduces soil water consumption. In this study, we monitored the jujube plots with control (CK), light (C1), medium (C2) and high (C3) pruning intensities during the jujube growing period of 2012–2015 to explore the effect of pruning intensity on soil moisture and water use efficiency (WUE) of jujube plantations in the hilly Loess Plateau Region. The results showed that pruning is an effective method for soil water conservation in jujube plantations. Soil moisture increased with increasing pruning intensity during the jujube growing period of 2012–2015. C1, C2 and C3 pruning intensities increased soil water storage by 6.1–18.3, 14.4–40.0 and 24.3–63.3 mm, respectively, compared to CK pruning intensity. Pruning promoted soil moisture infiltration to deeper soil layer. Soil moisture infiltrated to soil depths of 240, 280 and >300 cm under C3 pruning intensity, 220, 260 and 260 cm under C2 pruning intensity, 200, 240 and 220 cm under C1 pruning intensity, and 180, 200 and 160 cm under CK pruning intensity in 2013, 2014 and 2015, respectively. Soil water deficit was alleviated by higher pruning intensity. In 2013–2015, soil water change was positive under C2 (6.4 mm) and C3 (26.8 mm) pruning intensities but negative under C1 (−20.5 mm) and CK (−40.6 mm) pruning intensities. Moreover, pruning significantly improved fresh fruit yield and WUE of jujube plants. Fresh fruit yields were highest under C1 pruning intensity with the values of 6897.1–13,059.3 kg/hm2, which were 2758.4–4712.8, 385.7–1432.1 and 802.8–2331.5 kg/hm2 higher than those under CK, C2, and C3 pruning intensities during the jujube growing period of 2012–2015, respectively. However, C3 pruning intensity had the highest WUE values of 2.92–3.13 kg/m3, which were 1.6–2.0, 1.1–1.2 and 1.0–1.1 times greater than those under CK, C1 and C2 pruning intensities, respectively. Therefore, C3 pruning intensity is recommended to jujube plantations for its economic and ecological benefits. These results provide an alternative strategy to mitigate soil desiccation in jujube plantations in the hilly Loess Plateau Region, which is critical for sustainable cultivation of economic forest trees in this region.

Bunch number and antioxidant activity in ‘Sahebi’ and ‘Halagho’ grapes affected by pruning intensity and cane length

Pruning methods can primarily affect grape production at various levels. Of the commonly affected features by pruning, the number of bunches has known to have a significant effect on the relation between the functions of assimilate sources and sinks. Further, fruitfulness can significantly be negatively influenced by shading. In this study, we aim to study the impact of 4, 6 and 8 buds per cane with pruning intensity as light, moderate and severely pruned and their interaction in the course two consecutive years, 2017 and 2018 in ‘Sahebi’ and ‘Halagho’ (both seeded red table grape cultivars). In 2018, lightly pruned ‘Halagho’ and having 8 buds per cane increased number of bunches by 54.00, which had the highest value. Results showed that there is apical buds bear more fruit by comparison to the buds with vegetative nature, 1 to 4 first buds. Based upon the outcomes of this study, it could be concluded that due to the stresses imposed by the pruning of the vines, therefore, the chemical compounds increases in order alleviate the negative aftermaths . In 2018, whole berry antioxidant activity in both cultivars was significantly lessened, and this decline was higher in ‘Saahebi’. The number of bunches was increased by increasing cane length or bud load/cane. Overall, the pruning program has an impactful role in bunch number as well as antioxidant activity and in the long-run on accumulated reserves, which makes choosing and applying a specific pruning method undeniably important. Thus, emphasize the importance of further research in this field.

TOTAL PHENOLICS AND ANTHOCYANIN CONTENT OF TWO RED GRAPE (VITIS VINIFERA L.) CVS SAHEBI AND HALAGHO CULTIVARS AS AFFECTED BY PRUNING SEVERITY AND CANE LENGTH

A popular and important grape ‘Sahebi’ and a less known local grape ‘Halagho’ in Iran, were studied to unmask the influence of pruning severity and cane length on fruit bioactive potentials; total phenolic and anthocyanin content in which they affected significantly. In this investigation, effects of 4, 6 and 8 buds per cane with pruning intensity as light, moderate and severely pruned and their interaction in the course two consecutive years, 2017 and 2018 in ‘Sahebi’ and ‘Halagho’ were studied. Results revealed striking differences which in either cultivar, pulp phenolic content was 2 to 5 fold higher in 2017 compared to 2018 with the severely pruned ‘Halagho’ at the highest (5.14 mg/g DW). Whereas, lightly pruned ‘Halagho’ with 6 buds per canes had the highest peel anthocyanin content (1.09 mg/g DW), in the same condition but with severely pruning ‘Halagho’ showed the highest anthocyanin content in pulp (0.86 mg/g DW) while in the second year, 2018, severely or lightly pruned this type with 6 buds per cane had a significant increase in phenolic compound accumulation (10 mg/g DW). From the results of this experiment, it could be concluded that the pruning of the vines is a stressor and generates enhanced phytochemical constitutes to possibly mitigate the negative consequences. However, variation in the biochemical properties manifested a notable grape cultivar dependency in addition to the time factor, which was more pronounced in ‘Halagho’ than ‘Sahebi’. To some extent the effect of cultivars on the differences of two cultivars was predominant.

Reproductive Behaviour of Lemon (Citrus limon Burm.) Affected by Different Pruning Intensities and Integrated Nutrient Management Under Various Growing Seasons

The main objective of this study was to know the reproductive behaviour of lemon (Citrus limon Burm.) affected by different pruning intensities and integrated nutrient management under various growing season. The experiment was laid out in two factorial randomized block design with four levels of pruning, seven levels of nutrient, consisting recommended dose of fertilizers (RDF) and different combinations of organic manure (Vermicompost), inorganic fertilizer, biofertilizer (Azotobacter), Mycorrhiza (VAM) and their interaction to study their effect on plant reproductive behaviour during 2013–2015 on 9-year-old lemon plants in three growing seasons. The investigation revealed that the reproductive parameters, viz. number of flowers per plant, fruit set percentage and fruit yield, were found highest in lightly pruned plants fed with 75% RDF + Vermicompost + Azotobacter + Vesicular Arbuscular Mycorrhiza at Ambe, Mrig and Hasth bahar, respectively. Among the three seasons of cropping, Ambe bahar recorded the best result in respect to yield followed by Mrig and Hasth bahar.

Intercropping of Zingiber officinale Var. Amarum on teak silviculture in Karangduwet, Paliyan, Gunung Kidul Yogyakarta

This research aims to evaluate the influence of silvicultural technique (combination between singling and teak pruning) and ginger fertilizing in agroforestry plants productivity. Factorial random complete block design was used as experimental design, using three factors, that are teak pruning intensity, teak singling, and ginger fertilizing. Pruning intensity were P0 (without pruning) and P1 (60% pruning intensity), singling were S0 (without singling) and S1 (singling of teak coppice), and fertilizer intensity were J0 (without fertilizer) and J1 (5 ton/Ha of compost + 525 kg/ha of NPK). The research was conducted in teak private forest in Karangduwet, Paliyan, Gunung Kidul. The applied silvicultural technique system was clear cutting with coppice/sprout regeneration. Teak trees were the result of teak coppice in 2009 (6 years old). Result showed that singling gave significant influence to teak diameter growth (1.67 cm/1.5 year), while fertilizer gave significant influence to teak diameter (1.71 cm/1.5 year) and height growth (1.16 m/1.5 year). Moreover, teak pruning and ginger fertilizing gave significant influence to the resulted ginger wet weight. In this research, best ginger production (121.53 gram/clump) was found in the application of fertilizer combined with intercropping of pruned teak.

RESPONSE OF KINNOW CROP WITH RESPECT TO GROWTH, YIELD AND QUALITY TO DIFFERENT LEVELS OF PRUNING

Pruning is a technique that is employed in orchards to control growth, remove dead or diseased wood, to stimulate formation of flower and fruit buds. It has in common the objectives of manipulating the vegetative or reproductive growth. some of the benefit traditionally attributed pruning had been called into question by field research in past few decades. A proper training and pruning program is essential for maintenance of a healthy and productive orchard. To quantify the pruning intensity and level on the quality and yield in Kinnow fruit crop was studied in the department of Citrus Research institute, Sargodha from 2013 to 2015 . The research trial was conducted according to the RCBD with five replications. Mature and fruit bearing trees of Kinnow mandarin were pruned as No-pruning (T1), light-pruning 10 % (T2) , medium-pruning 25% (T3) and heavy-pruning 35 % (T4). Fruit yield per tree in terms of number of fruits was highest in third year in all contestant treatments i.e. 979 in medium-pruning, 957 in light-pruning, 929 in no-pruning and 853 in heavy-pruning. Medium pruning in respect of quality parameters like average fruit weight and juice percentage excelled among all treatments with results 223g and 54.6% respectively. Conclusively Maximum yield and quality of Kinnow fruit crop was obtained in medium-pruning which appeared to be the best pruning methodology in Kinnow crop

Canopy pruning as a strategy for saving water in a dry land jujube plantation in a loess hilly region of China

AimsSoil drying has occurred widely in artificial plantations in the semiarid loess region because the water consumption exceeds the rainfall. Jujube (Ziziphus jujube Mill. CV. Lizao) plantations have been planted to improve the economic income since 2000. In order to prevent soil drying and sustain artificial plantation development, we examined the relationships between the canopy size, water consumption, and water use efficiency in a dry land jujube plantation. MethodsSeven treatments were tested comprising native jujube with no pruning and dwarfing jujube under different pruning levels ranging from 1 to 6. Jujube is a popular dwarfing canopy type in this region with a tree height of 2.2 m and this comprised level 1. Jujube received increased intensities of pruning as well as decreases in tree height and canopy size for levels 2–4. Jujube received severe pruning to a tree height of only 1.1 m at level 5, and the canopy was removed with only 30–40 cm of the trunk left for level 6. Soil water was detected using CNC100 neutron tubes. A thermal diffusion probe was used to monitor the sap flow in jujube trees throughout the whole growth period. ResultsDuring our study period, 2014 was a wet year with rainfall of 460.4 mm and 2015 was a dry year with rainfall of only 380.8 mm. Transpiration and water consumption by jujube decreased significantly whereas the soil water content increased as the pruning intensity increased in these two years. Compared with 15-year-old native jujube, the annual soil water consumption by 15-year-old dwarfing jujube (pruned at level 1) was 6.54 mm less and the soil water consumption depth moved upward by 2.2 m. The soil water recovered faster for jujube at level 6 and the soil water restoration depth reached 4.6 m after 3 years, with an annual restoration depth of 153.3 cm. Compared with level 1 jujube, at level 5, the height was halved, the transpiration was about 22.1%, and the water use efficiency was significantly improved by 1.1 times, thereby demonstrating that the water consumption could be regulated by the canopy size. Level 2 jujube had the highest water use efficiency with the optimal pruning level in the local region. ConclusionsWe found that pruning could effectively decrease water consumption, relieve deep soil drying, and improve the water use efficiency in jujube. The pruning level should be determined based on the water consumption rate and average rainfall to obtain high yields.

Nature abhors a vacuum: Deciphering the vegetative reaction of the mango tree to pruning

Pruning is an important horticultural practice that generally promotes vegetative growth. However, the precise characterization of vegetative growth after pruning and of the factors affecting it are little known. The objective of this study was to decipher the vegetative response to pruning in a tropical evergreen species, the mango tree. Pruning was characterized by two factors: pruning intensity, defined at the tree scale as the amount of fresh biomass removed per unit volume of canopy, and pruning severity, defined at the axis scale as the distance between the pruning point and the distal end of the axis. Vegetative growth after pruning was broken down into structural (burst rate, vegetative growth intensity, leaf area produced) and temporal (burst date) variables, and the effects of pruning were evaluated on these variables at a local scale on pruned axes and at a distant scale on unpruned axes. Burst rate and leaf area produced increased with pruning intensity (pruned and unpruned axes), pruning severity (pruned axes), axis diameter (pruned and unpruned axes) and proximity to pruned axes (unpruned axes). Vegetative growth intensity increased with pruning severity (pruned axes) and axis diameter (pruned and unpruned axes) but was not affected by pruning intensity. For these three variables, local responses were more important than distant responses. The dynamics of vegetative growth was affected by pruning intensity and severity. Results depicted the complexity of mango tree response to pruning at different scales. As a general rule, more extensive pruning led to larger and more synchronous vegetative growth.

Harvest index of apple and kiwifruit – how high can we go by optimising plant architecture and canopy management?

Efficiency of plant function is measured using harvest index (HI), the fraction of annual fruit dry mass yield divided by the total annual dry mass of tree. HI describes the proportion of total annual biomass allocated into harvestable sinks. The HI of mature apple trees on dwarfing rootstocks is ~60-70%, higher than HI estimates of ~40% for kiwifruit vines. In a recent physiological study using tall spindle ‘Scilate’ (EnvyTM) apple planted intensively on M.9, a mature tree fruit yield of 105 kg tree(-1) fresh weight (175 t ha(-1) at 1667 trees ha(-1)) was achieved in the 9th year from planting. Average fruit dry matter content at harvest was 16.2%, suggesting a calculated annual dry weight fruit yield of 17 kg tree(-1) (28.3 t ha(-1)) in the 9th year. This mature tree yield was produced from minimal tree structure compared with traditionally-managed trees; the main axis and branches were slender in girth, and the mean dry weight of winter prunings following harvest in the 9th year was 0.62 kg tree(-1). Hence, high fruit yields were associated with little investment in standing tree structure and prunings, implying a very high tree physiological efficiency (HI). The HI of these ‘Scilate’ trees on M.9 in the 9th year was estimated to be 0.81. We speculate that HI of late season cultivars on M.9 could reach 0.85 with further optimisation of canopy management and tree architecture using artificial spur extinction. Exploiting vine architecture and optimising canopy management of kiwifruit may similarly improve yield and fruit quality by increasing vine HI. Preliminary results on whole vine behaviour (flowering, yield and vigour) in response to canopy architectural modification using spur pruning to reduce pruning intensity of ‘Zesy002’ (SunGold®) kiwifruit indicated that spur pruning did not modify yield but reduced vine dry weight of winter prunings by 50% after a single growing cycle. Ongoing work will compare vines managed by spur pruning and replacement cane pruning to quantify budbreak, flowering, yield and fruit quality responses over successive growing cycles.

Impact of simulated mechanical hedge pruning and wood age on new shoot demography and return flowering in olive trees

More vigorous watersprouts and fewer low vigor shoots form as wood age increases at the cutting points with greater canopy pruning depth in olive trees, which reduces return flowering. Such information is relevant to long-term olive orchard pruning strategies in hedgerows. Demographic analysis of growth responses to pruning in fruit trees seeks the quantification of the typology of new shoots originating from the remaining branches. Pruning of hedgerows using mechanical discs is becoming increasingly common in orchards, but little information is available as to how such pruning, which does not discriminate between branch size, wood age at the cutting point, branch type, or position, modifies subsequent new shoot demography. Hence, the experiment described in this study in young olive trees (cv. Arbequina) assessed the following questions: (1) Is the type and growth of new shoots associated with the intensity of mechanical pruning and/or the wood age on which they grow? (2) How many growing seasons does it take for new shoots formed after pruning to flower? The principal hypothesis was that a greater proportion of vigorous watersprouts form compared to low vigor shoots as wood age at the cutting points increases with canopy pruning depth, and that the watersprouts have low flowering potential. Both new shoot growth and return flowering were monitored on exposed supporting wood over several growing seasons after implementing three winter (25W, 50W, and 75W) pruning levels of increasing intensity and one summer pruning (75S) treatment along with an unpruned control (CON). As hypothesized, a greater number and elongation of vigorous watersprouts were found as wood age increased at the cutting points with greater winter pruning intensity, and the watersprouts had low levels of return flowering even 3 full years after pruning compared to the CON. Growth of low vigor shoots was relatively more important than watersprout growth in the severe summer pruning treatment, although 3 years after the summer pruning flowering was not fully recovered. In contrast, the more lightly pruned winter treatments (25W, 50W) did not show significant differences in flowering with the CON at the end of 3 years. Thus, mechanical hedge pruning in olive trees should be light-to-moderate to avoid the formation of watersprouts on older wood, which leads to long-term reductions in flowering.