Pruning Height Research Articles

Importance of plant architecture and plant density for rose crop performance

SummaryThe relationships between plant architecture and flower production of rose were studied for a cropping period of 2.5 years. Four types of plants, varying in number of basal shoots and their architecture were created, which were combined with three plant densities (7.7–11.6 and 17.4 plants per m2). Plant architecture was mainly managed by manipulation of the basal-shoot formation in combination with height of pruning and deshooting practices. The investment in stem mass significantly reduced the number and weight of flowers for the first eight months. This was due to a delay in time of basal shoot growth, restriction of number of outgrowing shoots and disbudding of shoots. However, this initial financial loss of about DFI 20 per m2 amply paid itself in the next two cropping years. Regression analyses showed that number and diameter of second-order laterals as formed after eight months, could explain more than 70% of the variation in number and weight of flowers harvested in more than two cropping ye...

Production and Postharvest Treatment of Cut Stems of Eucalyptus L. Hér. Foliage

Optimum pruning height for cut foliage production was investigated for 3-year-old trees of Eucalyptus globulus Labill. Trees cut at a height of 1.0 m above ground level had most stems resprouting from the trunk, but a pruning height of 0.5 m produced the longest stems. Postharvest trials were conducted to assess the vase life of cut stems, and the effect of pulsing and simulated transportation on vase life. Holding solutions containing 1% or 2% sucrose and 8-HQC at 200 mg·L–1 significantly increased vase life of E. globulus and E. cinerea F. Muell. ex Benth. over the control, but pulsing E. cinerea in 1%, 5%, or 10% sucrose plus 8-HQC for 2 hours at 24 °C or 24 hours at 3 °C had no effect. In simulated transport trials, pulsing overnight in 1% or 5% sucrose plus 8-HQC at 3 °C followed by 1 week dry storage at 3 °C had no effect on the vase life of cut stems of E. sideroxylon Cunn. ex Wools., E. platypus Hook., E. spathulata Hook., E. cladocalyx F. Muell. E. platypus, or E. spathulata E. sargentii Maiden, but a 5% sucrose pulse plus 8-HQC significantly increased the vase life of E. spathulata E. platypus. A long pulse at low temperature (24 hours/3 °C) followed by 1 week dry storage was more effective than a short pulse at high temperature (2 hours/24 °C) for E. albida Maiden & Blakely stems and no sucrose was more effective than 1% or 5%. Thus, a pruning height of 0.5 or 1.0 m was optimum for cut foliage production of E. globulus, and a 2% sucrose holding solution extended vase life. There was no advantage of sucrose pulsing to extend vase life, or to improve vase life following dry storage, except for the hybrid E. spathulata E. platypus. Chemical name used: 8-hydroxyquinoline citrate (8-HQC).

Controlling the plant development of Rosa hybrida ‘Motrea’

Influencing the development of rose plants after planting has been mainly focused on manipulation of the bottom-break formation. In this experiment, the plant development of Rosa hybrida cultivar ‘Motrea’ could be improved by certain plant treatments considering the diameter of the harvested shoots. Early plant development was highly affected by managing the pruning height of bottom breaks and subsequent flowering cycli and by controlling the number of outgrowing laterals on the remaining stem after harvesting. As a result of the treatments applied, an increase in the stem diameter of second order flowers and a decrease in the percentage of blind shoots, from 19% to 4%, could be achieved. Moreover, plant quality, defined as the sum of surface areas (mm 2) of the transverse section of the laterals at a height of 60 cm above soil level, 9 months after planting, was improved by more than 50%. Bush management on distribution of assimilates over an optimal number of developing shoots is discussed. The close relation between the initial quality (diameter) of bottom breaks and plant quality 9 months after planting together with the observed differences on plant development between ‘smaller’ and ‘bigger’ plants, stressed the importance of uniform plant material and an optimal control on the process of bottom-break formation.

Estudos sobre a nutrição mineral do cafeeiro: XL. Fitomassa e conteúdo de macro e micronutrientes no material podado

Foi conduzido um ensaio numa plantação comercial de café de variedade Mundo Novo de 9 anos de idade, com uma população de 1904 covas/ha, destinada a avaliar a quantidade de biomassa e de nutrientes removidas por diferentes tipos de poda: recepa a 0,40m; decote a 1,00, 1,50 e 2,00 m; decote a 1,50m com esqueletamento. A análise do material e dos dados permitiu tirar-se as seguintes conclusões: (1) a biomassa removida pela poda foi maior na recepa (24,3 t de matéria fresca e 11,9 de matéria seca) e no decote a 1,00 m (20,6 e 10,1 t, respectivamente); seguia-se o decote a 1,50 m com esqueletamento que deu 19,4 e 8,3 t de matéria fresca e seca por hectare; os pesos da matéria fresca e seca correspondentes aos decotes a 1,50 m e 2,00 m foram: 12,1 e 5,4; 5,6 e 2,5 t/ha; (2) a relação existente entre a altura de poda e quantidade de fitomassa removida é descrita por equações de regressão simples; (3) as quantidades de nutrientes removidas são proporcionais as quantidades de material podado sendo as seguintes de acordo com a ordem dos tratamentos dado, em kg/ha: N - 320, 294, 162, 80 e 261; P - 18, 15, 10, 44 e 16; K - 286, 266, 168, 78 e 273; Ca - 149, 139, 63, 33 e 101: Mg - 30, 33, 16, 8 e 26; S - 10, 7,6, 3 e 10; as quantidades de micronutrientes removidas foram, em g/ha: B - 306, 337, 163, 83 e 268; Cu - 229, 219, 121, 51 e 191; Fe - 2783, 2328, 1367, 544 e 2,088; Mn - 437, 779, 264, 142 e 412; Zn - 174, 152, 74, 28 e 121; (3) foram derivadas equações de regressão simples que relacionam quantidade extraídas e altura da poda; (4) a reciclagem de fitomassa contribui com economia substancial de fertilizantes para a nova vegetação. Cerca de dois terços e três quartos de nutrientes, entretanto, estão contidos no material lenhoso de caules e ramos o que deve fazer que a sua disponibilidade seja mais lenta.

Perspectives on hedgerow intercropping

Hedgrow intercropping (alley cropping) is a relatively new technology involving growing agricultural crops between rows of planted tree species. Leucaena is the most widely studied tree species for the practice and research has indicated that it can yield over 200 kg ha−1 year−1 of nitrogen for application in the alleys where crops are planted. More herbage (and nitrogen) are obtained from narrow alleys, and crops utilise the nitrogen better if the prunings are incorporated into the soil before planting. Low pruning heights may prevent shading of the crops.

HIGH PRUNING IN PINUS PATULA, ITS FEASIBILITY, EFFECT ON GROWTH AND ECONOMICS

Summary The history of State coniferous pruning policy in South Africa is briefly reviewed. Current pruning practice makes provision for pruning up to a height of 22 feet only and a large percentage of all timber produced will therefore be unaffected by pruning and will be of inferior quality with a high percentage of defective knots. The only solution to this problem will be an increase in the height of pruning and an experiment was laid out at Middlebrook plantation to test the practicability of three high pruning treatments and also their effect on growth. Of the treatments tested, pruning from 22 feet to 36 feet, at a mean tree height of 50 feet, is to be preferred. This treatment not only had a negligible effect on growth but was found to be perfectly feasible, provided that suitably constructed ladders were used to enable the pruners to reach the lower branches of the trees. Light metal ladders should be ideal but are likely to prove too expensive for general use. After metal, bamboo ladders will probably be the best although ladders made from suitable poles or sawn timber would also be satisfactory. From the point of view of the production of clear timber pruning from 22 feet to 36 feet is going to be of doubtful value. This degree of pruning will, however, entirely eliminate defective knots in approximately one fifth of the total volume of the tree and the resultant increase in value of this timber should far outweigh pruning costs.