Differences In Vegetative Growth Research Articles

Multiomics Analyses Reveal the Dual Role of Flavonoids in Pigmentation and Abiotic Stress Tolerance of Soybean Seeds.

The color of the seed coat has great diversity and is regarded as a biomarker of metabolic variations. Here we isolated a soybean variant (BLK) from a population of recombinant inbred lines with a black seed coat, while its sibling plants have yellow seed coats (YL). The BLK and YL plants showed no obvious differences in vegetative growth and seed weight. However, the BLK seeds had higher anthocyanins and flavonoids level and showed tolerance to various abiotic stresses including herbicide, oxidation, salt, and alkalinity during germination. Integrated metabolomic and transcriptomic analyses revealed that the upregulation of biosynthetic genes probably contributed to the overaccumulation of flavonoids in BLK seeds. The transient expression of those biosynthetic genes in soybean root hairs increased the levels of total flavonoids or anthocyanins. Our study revealed the molecular basis of flavonoid accumulation in soybean seeds, leveraging genetic engineering for both nutritious and stress-tolerant soybean germplasm.

Fixed vs. variable light quality in vertical farming: Impacts on vegetative growth and nutritional quality of lettuce.

Lettuce (Lactuca sativa) is commonly produced in vertical farms. The levels of nutritionally important phytochemicals such as beta-carotene (precursor to vitamin A) are generally low in lettuce. In this study, we investigated the benefits of variable lighting strategy (i.e., varying the light quality during production) on maintaining plant growth and increasing the biosynthesis of beta-carotene and anthocyanin. We tested two variable lighting methods, using green and red romaine lettuce, namely (i) providing growth lighting (supports vegetative growth) initially (21 days) followed by a high percentage of blue light (supports biosynthesis of phytochemicals) at final stages (10 days) and (ii) providing a high percentage of blue light initially followed by growth lighting at final stages. Our results indicate that the variable lighting method with initial growth lighting and high percentage of blue at final stages can maintain vegetative growth and enhance phytochemicals such as beta-carotene in green romaine lettuce while both variable lighting methods were not effective in red romaine lettuce. In green romaine lettuce, we did not observe a significant reduction in shoot dry weight but there was an increase in beta-carotene (35.7%) in the variable compared to the fixed lighting method with growth lighting for the entire duration. The physiological bases for differences in vegetative growth and synthesis of beta-carotene and anthocyanin in the variable and fixed lighting methods are discussed.

Use of sensor based drip irrigation in improving irrigation water efficiency for vegetable crops Tharaka Nithi county

Drip irrigation is a water saving technology recommendable for ASAL regions of Kenya that are water deficit. However, it is largely manually operated in Kenya, leading to variable irrigation water use efficiency (IWUE). This necessitates automating the irrigation. Sensor based irrigation has been developed at Meru University of Science and Technology. In this study, the system was configured for use in ASALs areas of Kenya. The system has an electronic gadget designed to automate irrigation. It is fitted with soil moisture sensors and motorized water valves. The sensors are installed near the crop root zone. When soil moisture drops below a predetermined threshold, the pump and the valves are triggered to switch ON automatically and start supplying water to the crops. When adequate water has been supplied, the sensors detect trigger the pumps and motorized valves to switch OFF hence cutting the water supply to the crops. The system was validated at Mukothima in Tharaka Nithi, an ASAL region in Kenya between April and August 2021 using water melon (Sukari F1) and onion (Red creole) as test crops. A randomized complete block design with three replications was used with three irrigation systems; sensor based drip, manually drip and furrow irrigation. Data was collected on vegetative growth and yield, soil moisture and irrigation water used. Farmers were invited to evaluate the crops during the vegetative stage. There were no significant differences in vegetative growth and fruit yield of water melon and bulb yield of onions between the irrigation systems. Soil moisture tended to be high in furrow irrigation. Irrigation water used was significantly higher in furrow irrigation and lowest in the sensor based drip irrigation. This led to a significantly higher IWUE in sensor based drip irrigation. Farmers evaluation did not detect significant differences in the crops between the irrigation systems. It is concluded that use of sensor based drip irrigation is able to enhance efficiency of irrigation water use while at the same time giving productivity of crops similar to the common methods of irrigation used in ASALs.

Effect of Pectimorf on the rooting ability, and morpho-physiological trials of national cocoa (Theobroma cacao L.) under different substrates

Cocoa is an economical cash crop that is formerly planted worldwide. Cuttings are a method of vegetative propagation suitable for maintaining desirable characteristics in cocoa trees. A greenhouse experiment was performed to evaluate the optimal concentrations of Pectimorf® (0, 10, 50, and 100 mg L-1) for rooting ability and seedling establishment as well as some physiological trials of 4 months EETP-800 national cocoa cuttings grown under two different substrates (S1: 80% soil + 20% sand and S2: 70% soil + 20% sand + 10% rice husk). The data showed that in most cases there are no significant differences in vegetative growth and root characteristics as well as gas exchange parameters between the two substrates. On the other hand, the application of Pectimorf® concentration enhanced all tested traits compared to untreated plants. The most effective in this regard was 100 mg L-1, that giving the highest value of all trials. As for the interaction effect, the result also shows that the application of Pectimorf® concentration in special at 100 mg L-1 among two substrates had an additive effect on plant growth, gas exchange, and survival percentage compared to non-treated cuttings. The application of 100 mg L-1 Pectimorf® with S2 substrate produced stronger seedlings with a higher survival percentage. This protocol can be used commercially for cocoa propagation commercially.

Sex-Specific Physiological Responses of Populus cathayana to Uranium Stress

Attention is increasingly being paid to the contamination of soil by the radioactive element uranium (U). Phytoremediation of contaminated soil by economically advantageous and environment-protective plants shows considerable potential for addressing this problem. Populus cathayana is a species with high heavy-metal tolerance, economic value, and notable potential for phytoremediation. Plant-sex-related differences can lead to differences in vegetative growth and tolerance to various stressors. As such, in this study, we designed a pot experiment to analyze the responses of male and female trees of P. cathayana to 50 mg kg−1 U stress in contaminated soil for 3 months. We studied the U uptake and distribution, photosynthesis, chlorophyll fluorescence, active oxygen species, and antioxidant enzymes of P. cathayana. The results showed that the photosynthetic activity and chlorophyll fluorescence of male and female trees were similar, and U stress mainly affected the nonstomatal factors and photosystem II during photosynthesis. Regarding the physiological and biochemical processes, male and female trees showed different defense strategies: male trees had higher peroxidase (POD), H2O2, and soluble sugars, but lower malondialdehyde (MDA), superoxide dismutase (SOD), and soluble proteins. Under U stress, the active oxygen produced by male trees could be cleared by antioxidant enzymes, preventing damage to the cell membrane. Male trees accumulated a higher U concentration in their roots than female trees, whereas the transportation of U from roots to leaves in male trees was lower than that in female trees. Therefore, our results suggested that male trees have a higher tolerance capacity and greater ability to remediate U-polluted soil than female trees. Future phytoremediation studies should consider the differences between plant sexes in the tolerance to U-contaminated land.

A C2H2 Zinc Finger Protein PlCZF1 Is Necessary for Oospore Development and Virulence in Peronophythora litchii.

C2H2 zinc finger is one of the most common motifs found in the transcription factors (TFs) in eukaryotes organisms, which have a broad range of functions, such as regulation of growth and development, stress tolerance and pathogenicity. Here, PlCZF1 was identified to encode a C2H2 zinc finger in the litchi downy blight pathogen Peronophythora litchii. PlCZF1 is conserved in P. litchii and Phytophthora species. In P. litchii, PlCZF1 is highly expressed in sexual developmental and early infection stages. We generated Δplczf1 mutants using the CRISPR/Cas9 method. Compared with the wild type, the Δplczf1 mutants showed no significant difference in vegetative growth and asexual reproduction, but were defective in oospore development and virulence. Further experiments revealed that the transcription of PlM90, PlLLP and three laccase encoding genes were down-regulated in the Δplczf1 mutant. Our results demonstrated that PlCZF1 is a vital regulator for sexual development and pathogenesis in P. litchii.

Stimulatory effects of growth-promoting bacteria on growth, nutritional composition, and yield of kale plants

Plant growth promotion using beneficial bacteria is an eco-friendly approach to meet the worldwide need for raising crop yields. This research was done in a greenhouse during 2017 and 2018 seasons to investigate the effect of bacterial biofertilization using three strains, AP-28 of Pseudomonas koreensis, AP-29 of Ralstonia pickettii, and AP-51 of Bacillus cereus on kale plants. Seeds of kale plants were soaked in bacterial solutions for three hours and compared with untreated seeds. Our results exhibited that the highest significant differences in vegetative growth, including plant length (16.76 and 15 cm), leaf number (14.33 and 14.00), and leaf area (100.52 and 99.73 cm2) were obtained from AP-51 treatment compared with control (11.33 and 10.67 cm), (10 and 11.67) and (100.52 and 99.73 cm2) in both seasons, respectively. In both seasons, seed treatment with AP-51 produced the highest significant ascorbic acid (1.373 and 1.309 mg/g) compared with control (6.82 and 8.23 mg/100g, respectively). The highest phenolic contents in both seasons were produced by AP-51 (1.83 and 2.10 mg/g) compared to untreated plants (1.31 and 1.46 mg/g, respectively). AP-51 recorded the highest yield (95.81 and 94.75 g/plant) compared with control (72.92 and 82.76 g/plant) in both seasons, respectively. Macronutrients (N, P, K, Ca, and Mg), as well as microelements (Fe, Cu, and Zn), were examined. The treatment with plant growth-promoting bacteria has been recognized as an environmentally sustainable approach to reduce the inputs of chemical fertilizers and to increase crop productivity, phytochemical composition, and mineral contents.

Pertumbuhan dan Hasil Dua Varietas Ubi Kayu pada Empat Dosis Pupuk Npk di Lahan Pasang Surut Kalimantan Selatan

Tidal acid land is a potential land for cassava development. However, the development of cassava in tidal land faces many obstacles, one of which is the low availability of nutrients. This study aimed to determine the effect of NPK fertilizer in increasing the growth and yield of cassava in tidal land. The experiment consisted of two factors, the first factor was two varieties of cassava and the second factor was four levels of NPK fertilizer doses. The experiment was applied in a strip plot design with variety as the horizontal factor and the level of NPK fertilizer as the vertical factor and repeated three times. The growth parameters observed consisted of plant height, stem diameter, plant biomass weight, number of large tubers, number of small tubers, large tuber length, length of small tuber, the diameter of large tuber, the diameter of small tuber, the total number of tubers, the weight of large tuber, the weight of tuber small, and total tuber weight. The results showed that fertilizer application was effective in increasing vegetative growth and yield of cassava but increasing the dose of fertilizer was not effective in increasing the growth and yield of cassava. Differences in varieties generally did not show differences in vegetative growth and some yield components but still showed different results in the components of tuber length and total tuber weight.

The Mitogen-Activated Protein Kinase PlMAPK2 Is Involved in Zoosporogenesis and Pathogenicity of Peronophythoralitchii.

As an evolutionarily conserved pathway, mitogen-activated protein kinase (MAPK) cascades function as the key signal transducers that convey information by protein phosphorylation. Here we identified PlMAPK2 as one of 14 predicted MAPKs encoding genes in the plant pathogenic oomycete Peronophythora litchii. PlMAPK2 is conserved in P. litchii and Phytophthora species. We found that PlMAPK2 was up-regulated in sporangium, zoospore, cyst, cyst germination and early stage of infection. We generated PlMAPK2 knockout mutants using the CRISPR/Cas9 method. Compared with wild-type strain, the PlMAPK2 mutants showed no significant difference in vegetative growth, oospore production and sensitivity to various abiotic stresses. However, the sporangium release was severely impaired. We further found that the cleavage of the cytoplasm into uninucleate zoospores was disrupted in the PlMAPK2 mutants, and this developmental phenotype was accompanied by reduction in the transcription levels of PlMAD1 and PlMYB1 genes. Meanwhile, the PlMAPK2 mutants exhibited lower laccase activity and reduced virulence to lychee leaves. Overall, this study identified a MAPK that is critical for zoosporogenesis by regulating the sporangial cleavage and pathogenicity of P. litchii, likely by regulating laccase activity.

Field management of Rotylenchulus reniformis on pineapple combining crop rotation, chemical-mediated induced resistance and endophytic bacterial inoculation

In Martinique or La Réunion, French authorities recently banned the use of pesticides for the management of “soil-borne pathogens” on pineapple after several decades of intensive monoculture where the natural balance between beneficial and harmful communities of soil organisms has disappeared. Today, increasing infestation of pineapple by the nematode R. reniformis and other “soil-borne pathogens” causes severe damage to the crop. New cropping systems with innovative ecological nematode management are needed. An eco-friendly cropping system, which comprised rotation of sunn hemp (C. juncea), pineapple, a natural grass fallow and another cash crop, eggplant, consistently reduced the inoculum of nematodes. Nematode populations were reduced by 86.4%, 82% and 46.5% respectively under pineapple, sunn hemp and grass fallow compared to infestations of eggplant (3456 nematodes .100g-1 of soil) after several rotations. Integrating a chemical induction of systemic resistance or application of an endophytic bacteria recovered from pineapple roots, Bacillus sp. GVS2, helped maintain low populations of nematodes during the vegetative cycle. On two pineapple varieties, MD2 and Victoria (Queen), two different treatments were applied monthly in the field, methyl jasmonate (10−4 M, 10 ml per plant), or a suspension of Bacillus sp. GVS2 (108 CFU ml−1, 10 ml per plant) isolated from pineapple roots. After eight months, the nematode populations were reduced respectively on MD2 and Victoria (Queen) by 58.3% and 50.3% with the methyl jasmonate and by 59.6% and 54.3% with the Bacillus sp. GVS2 compared to controls. Because of the efficiency of sunn hemp in reducing the inoculum of nematodes, no significant differences in vegetative growth were observed using the D leaf weight and the estimated root length densities (RLD). The potential of pest management through eco-friendly cropping systems for pineapple with a biocontrol for nematodes with no pesticide is discussed.

FT-IR biomarkers of sexual dimorphism in yerba-mate plants: Seasonal and light accessibility effects

In dioecious species, plants of different genders can show differences in vegetative growth (secondary sexual dimorphism) which can impact the quality of their nutritive products. The effect of sexual dimorphism in metabolic changes of Ilex paraguariensis (yerba-mate) leaves was investigated by Fourier-transform infrared spectroscopy (FT-IR) combined with the chemometric tools of principal component analysis (PCA) and ANOVA-simultaneous component analysis (ASCA), when plants experienced diverse light availabilities during two plant phenophases (seasons). Fingerprints of yerba-mate leaves were obtained by a statistical mixture design of four components (ethanol, ethyl acetate, dichloromethane and hexane). In yerba-mate leaves harvested in the shade and in clearings during the spring, caffeine was identified as a possible biomarker for male plants, while pheophytin a was found for females. Leaves harvested during the winter in shaded areas and clearings showed the same pattern of FT-IR biomarkers as for spring harvest. The sexual dimorphism factor had a significant influence on the FT-IR spectral fingerprints of yerba-mate confirming caffeine for male plants and pheophytin a for females as possible biomarkers. Furthermore, a metabolic change in the two genders was pointed out, regardless of external factors. The use of the statistical mixture design was essential for obtaining the maximum possible diverse extraction of metabolites and to ensure greater analysis robustness. Knowledge regarding metabolites related to sexual dimorphism in yerba-mate leaves is essential to increase understanding of the metabolic role in plant functioning and in the final product quality obtained from leaves.

Differences in vegetative growth of two invasive hawkweeds at temperatures simulating invaded habitats at two altitudes

Hieracium pilosella and H. aurantiacum are invading alpine regions in New South Wales, Australia. In a glasshouse experiment we investigated germination and growth rates of these two species at temperatures simulating the altitudes where invasions are occurring from autumn to spring. We measured germination rates, growth rates and the development of stolons and ramets using seedlings and plantlets from established plants. Germination was low in H. aurantiacum and unaffected by altitude or seed age. H. pilosella showed site to site variability in germination but had greater germination. No species produced flower spikes. Both species grew rapidly and put at least twice as much biomass into roots compared to shoots. H. aurantiacum could begin to produce stolons after 27 days and seedlings grew a little larger than for H. pilosella. Hieracium aurantiacum put significantly more resources into ramets, allocating between 4–15% of biomass. H. pilosella produced 2.6 stolons month−1, in contrast to 9.8 stolons month−1 for H. aurantiacum. Furthermore, plantlets from established plants had vastly different growth rates. Plantlets of H. aurantiacum produced 2.1 leaves day−1 from late summer to winter where H. pilosella was 3 times slower for the same period but faster following winter. Both species were able to maintain strong growth over cooler months suggesting hawkweeds have the capacity for fast growth in the invaded range under high nutrients and lower competition. H. aurantiacum is likely to be a more effective invader than H. pilosella spreading through stolons and the development of weed mats.

Requirement of LaeA, VeA, and VelB on Asexual Development, Ochratoxin A Biosynthesis, and Fungal Virulence in Aspergillus ochraceus.

Aspergillus ochraceus is reported to be the major contributor of ochratoxin A (OTA), classified as one of the possible human carcinogen (group 2B) by the International Agency for Research on Cancer. The heterotrimeric velvet complex proteins, LaeA/VeA/VelB, have been most studied in fungi to clarify the relation between light-dependent morphology and secondary metabolism. To explore possible genetic targets to control OTA contamination, we have identified laeA, veA, and velB in A. ochraceus. The loss of laeA, veA, and velB yielded mutants with differences in vegetative growth and conidial production. Especially, ΔlaeA almost lost the ability to generate conidiaphore under dark condition. The deletion of laeA, veA, and velB drastically reduced the production of OTA. The wild-type A. ochraceus produced about 1 and 7 μg/cm2 OTA under light and dark conditions on media, whereas the three gene deletion mutants produced less than 20 ng/cm2 OTA, which was correlated with a down regulation of OTA biosynthetic genes. Pathogenicity studies of ΔlaeA, ΔveA, and ΔvelB showed their reduction in disease severity in pears. Furthermore, 66.1% of the backbone genes in secondary metabolite gene cluster were significantly regulated, among which 81.6% were downregulated. Taking together, these results revealed that velvet complex proteins played crucial roles in asexual development, secondary metabolism, and fungal virulence in A. ochraceus.

The Effects of Different Tillage Systems and Cultivars on Growth, Yield and Quality of Zucchini (Cucurbita pepo L.) in a Semi-Arid Sub-Tropical Environment

Conservation agriculture is a concept for resource-saving agricultural crop production system that serves to achieve acceptable profits and sustaining production while conserving the environment. The popularity of zucchini also known as baby marrow in the Kingdom of Eswatini has increased in recent years specifically for its economic value in the foreign market. This study was carried out at Malkerns Research Station, Malkerns in the Middleveld of the Kingdom of Eswatini to assess the effectiveness of different tillage methods and cultivars on growth, yield and quality of zucchini. The tillage methods used were zero, basin and mulch tillage. Furrow tillage was used as a control. The results showed that tillage methods had significant (P<0.05) differences in growth and yield of zucchini. Minimum tillage plants exhibited lowest number of leaves (9.5), vine length (36.4 cm), leaf area index (2.5) and number of flowers (6), number of fruits (1.3) and marketable yield/plant (4.6 ton/ha). Non-significant (P>0.05) differences were obtained from plants grown under basin, mulch and furrow tillage. The highest vine length (69.6cm), leaf number (17.0), LAI (3.6), and marketable yield (15.7 ton/ha) were obtained in zucchini plants grown under basin tillage system. However, there were no significant (P>0.05) differences in accumulation in leaves of zucchini plants of mineral content. In terms of the cultivars there were no significant (P>0.05) differences in vegetative growth. Star 8023 showed superiority in terms of number of fruits and marketable yield. It was observed that minimum tillage was less suitable in zucchini production as compared to other tillage systems. For higher production in zucchini, basin, furrow and mulch may be used. The best cultivar to use is star 8023.

Genomic Analysis of the Insect-Killing Fungus Beauveria bassiana JEF-007 as a Biopesticide

Insect-killing fungi have high potential in pest management. A deeper insight into the fungal genes at the whole genome level is necessary to understand the inter-species or intra-species genetic diversity of fungal genes, and to select excellent isolates. In this work, we conducted a whole genome sequencing of Beauveria bassiana (Bb) JEF-007 and characterized pathogenesis-related features and compared with other isolates including Bb ARSEF2860. A large number of Bb JEF-007 genes showed high identity with Bb ARSEF2860, but some genes showed moderate or low identity. The two Bb isolates showed a significant difference in vegetative growth, antibiotic-susceptibility, and virulence against Tenebrio molitor larvae. When highly identical genes between the two Bb isolates were subjected to real-time PCR, their transcription levels were different, particularly in heat shock protein 30 (hsp30) gene which is related to conidial thermotolerance. In several B. bassiana isolates, chitinases and trypsin-like protease genes involved in pathogenesis were highly conserved, but other genes showed noticeable sequence variation within the same species. Given the transcriptional and genetic diversity in B. bassiana, a selection of virulent isolates with industrial advantages is a pre-requisite, and this genetic approach could support the development of excellent biopesticides with intellectual property protection.

Effect of Ridging on the Performance of Young Grapevines on a Waterlogged Soil

The effect of ridging on root development, vegetative growth and yield of young grapevines, cv. Chenin blanc/99R, was studied in a field trial on a soil naturally waterlogged during winter and early summer. Ridging tended to improve root efficiency as ell as general grapevine performance compared to unridged soil. There was no significant difference in vegetative growth of grapevines planted on 400 mm-high double row, 600 mm-high double row or 400 mm high single row ridges. Yield, however, decreased where the surface to volume ratios of double row and single row ridges were less than 0,6 and 1,0 respectively. This implied that excessively dry and warm soil conditions had occurred during ripening where the ridges were too large. Irrigation in combination with ridging resulted in significantly improved vegetative growth and higher yield compared to the unripped control treatment. Preliminary ripping of compacted subsoil to a depth of 550 mm tended to improve vegetative growth and yield of ridged as well as unridged treatments. Ridging had no significant effect on total soluble solids, total titratable acidity and pH of musts.

The relative contribution of grazing and climate variation on vegetation change in alpine area

For more than a decade, a warming and grazing experiment has been carried out in the alpine area of the Faroe Islands. Ten Open Top Chambers (OTCs) were placed inside an enclosure with control plots both inside (CtrlE) and outside (CtrlO) the enclosure. The difference in vegetative growth of the two species Salix herbacea and Polygonum viviparum and graminoids were monitored as well as the frequencies of the four functional types: herbs, graminoids, woody species and bryophytes. It was found that warming generally increased leaf length by around 30% with similar or larger increases in photosynthetic leaf area. Grazing reduced leaf length by around 30% for graminoids and Polygonum viviparum, but only by around 10-20% for Salix herbacea. The changes in frequencies of functional types were most pronounced for bryophytes and woody species during the latter part of the experiment when both grazing-exclusion and warming increased the frequencies of bryophytes and decreased the frequencies of woody species.

Identification of double-stranded RNA viruses in Brazilian strains of Metarhizium anisopliae and their effects on fungal biology and virulence

Brazil is the leading country in the use of the entomopathogenic fungus Metarhizium anisopliae against agricultural pests. Very little information has been documented about the diversity and the impact of mycoviruses on M. anisopliae compared to M. robertsii and M. brunneum. This study reports the discovery of mycoviruses associated with native Brazilian Metarhizium spp. strains from the entomopathogen collection of the University of São Paulo, including strains used for mass-production of aerial conidia in sugar-alcohol factories to meet their own demand for controlling sugarcane spittlebugs and used in commercial mycoinsecticides. We also investigated the potential effects of viral infection on the biological traits of some of these strains. Viral-like double-stranded RNA (dsRNA) was found in 61% of the 36 Metarhizium spp. strains analyzed and showed a large variation of different electrophoretic banding patterns consisting of 2 to 8 dsRNA bands in polyacrylamide gels (PAGE). No dsRNA was detected in any of the strains from commercial products used in this study. Efforts to “cure” strains with dsRNA revealed that the inhibitor of protein synthesis cycloheximide was not efficient in eradicating dsRNA viruses from Metarhizium spp. strains. Some dsRNA segments of M. anisopliae ESALQ 26 were lost following hyphal tip subculturing. The dsRNA-variants of M. anisopliae strains ESALQ 866, ESALQ 1256 and ESALQ 1595 were healed after either monoconidial or hyphal tip subculturing. Single spore cultures of M. anisopliae ESALQ 1256 exhibited significant differences in vegetative growth, conidia production, and virulence against Tenebrio molitor larvae, although these differences were not linked with dsRNA. Moreover, fungal variants free of or positive for dsRNA had similar heat and UV tolerance responses. Our results suggest that viral-like dsRNA are very common among Brazilian M. anisopliae strains, but there is sparse evidence that these mycoviruses are harmful to fungal biological traits.

Role of irrigation scheduling and irrigation interval on consumptive use and growth of cowpea at middle of Iraq

A field experiments was conducted during spring season 2015 at the Agricultural field of Veterinary College - Baghdad University. In order to study the effect of irrigation interval in water requirements growth and yield of cowpea by using irrigation scheduling based on applied irrigation water (IW) and accumulative pan evaporation (CPE) which represented empirical pan factor (Ef). Six-irrigation treatment ware chosen (Ef 0.6, Ef 0.8, Ef 1.0, Ef 1.2, Ef 1.4, and Ef 1.6). The results showed that the irrigation interval was variable values and is decreased by increasing Ef value and with the progress of growing season. The 1.2 IW:CPE and 1.0 IW:CPE treatments with approximately 3-4days irrigation interval was achieved the best in subsequent results. The results showed that the total amount of water applied of Cowpea grown during spring season was 254.82mm, as a mean based on IW:CPE ratio. The data showed that there were significant differences in vegetative growth of cowpea crop such as plant height, number of branches per plant, biological yield. Pod length, pod circumference, fresh pods yield weight of loosed and number of seed/pod. The results of the effect of irrigating treatments on cowpea seed yield and its components showed that treatment Ef 1.2 was superior in fresh seed yield by, 5.13 6.88 and 7.33 ton hec-1.

Irrigation management of greenhouse zucchini with different soil matric potential level. Agronomic and environmental effects

Greenhouse horticultural crops are characterized by high levels of efficiency and productivity of irrigation water. But they still can and must be improved, especially in arid areas. The objective of this research was to study the effect of the soil matric potential level on the bio-productivity of zucchini crop, the water use efficiency (WUE) and nutrients use efficiency by changing the threshold of soil matric potential. An experiment was conducted in greenhouse-grown zucchini on a sand-mulched soil and fertigation with inorganic fertilizer. Automatic activation of irrigation through an electronic tensiometer and three treatments were applied: Activation of irrigation to −10kPa and application of volume of 1.5Lm−2 (T1), activation of irrigation to −25kPa and application of volume of 2.0Lm−2 (T2) and activation of irrigation to −40kPa and application of volume of 3.0Lm−2 (T3). Yield, leaf area, biomass, water consumption, WUE and nutrients, drainage volume and physical-chemical parameters of the soil were determined. The results show that T2 slightly reduced the weight of the fruit with respect to T1, but not the number of fruit, obtaining a significantly lower consumption of water. Lower weight fruits and less number of fruits were obtained by T3. Reducing the soil moisture tension level increased substantially water consumption as a result of the differences in vegetative growth (leaf area and biomass) in plants. Highest values of WUE and nutrients use efficiency were registered by T2 and T3. In none of the treatments, drainage was obtained. Soil physical-chemical parameters were not affected by treatments. Independently of soil matric potential, increased soil salinity occurred after the growing season. The soil matric potential of −25kPa was the best considering agronomic and environmental aspects, as the most efficient use of water and nutrients obtaining a commercial production of 15kgm−2.