Aliyeh Shafiei; Mehdi Hadadinejad; Saeed eshghi; kamran ghasemi
Abstract
The present research tries to investigate the effect of potassium silicate and mycorrhizal fungus on heat stress tolerance of strawberries and evaluate the possibility of increasing plant tolerance to heat at research greenhouse in Sari Agriculture and Natural Resources University at 2019. It is in a ...
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The present research tries to investigate the effect of potassium silicate and mycorrhizal fungus on heat stress tolerance of strawberries and evaluate the possibility of increasing plant tolerance to heat at research greenhouse in Sari Agriculture and Natural Resources University at 2019. It is in a completely randomized factorial design with three factors including two levels of mycorrhizal fungi (presence and absence of mycorrhizal fungi), three levels of potassium silicate (0, 50 and 100 mg.l-1) spray in heat stress (25 and 41 °C) with three replications. The results show that application of potassium silicate reduces the Photosynthtic active radiation (PAR) damage in strawberry leaves, which PAR of leaves bottom reduce three folds in comparison to the control, when the PARtop is 1133 umol.m2.s-1. In contrast, treatment of the plant with potassium silicate in the presence of mycorrhiza prevented increases transpiration and stomatal conductivity for water cooling the leaves during heat stress. Inoculation of the roots with mycorrhiza fungi leads to a wide network of hyphae in root uptake, improving water use efficiency by up to 72%, which in turn results in increaseed net photosynthesis. However, heat stress increases minimum fluorescence and reduces maximal quantum efficiency of photosystem II. But the simultaneous application of mycorrhiza and potassium silicate is able to improve this index to a good level (0.76). Finally, it has been found that high temperature stress affects many photosynthetic factors of strawberry plant that the use of potassium silicate in combination with mycorrhizal fungus, despite their separate use, to a large extent prevents heat damage to different parts of the plant.
Amirali Mohammadi; Mehdi Hadadinejad; hosein sadeghi; Kamran Ghasemi
Abstract
Blackberry is a temperate plant that can also be grown in the greenhouse for off-season fruit production as well as greater profit. This study is conducted as a factorial experiment in a completely randomized design with three replications as a pot inside the soil. The first factor has been the cultivar ...
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Blackberry is a temperate plant that can also be grown in the greenhouse for off-season fruit production as well as greater profit. This study is conducted as a factorial experiment in a completely randomized design with three replications as a pot inside the soil. The first factor has been the cultivar (early, intermediate, and late) and the second one is the nutrition program at six levels of NPK(N0P0K0(control), N0P0K0, N50P0K25, N50P0K50, N50P25K50, and N50P12.5K25 kg/ha), applied as fertigation. Results show that the use of nutrients release the highest amount of nitrogen and potassium in the late cultivar. The highest shoot length and chlorophyll index belong to N50P0K25 treatment. Furthermore, blackberry’s response to different ratios of nutrients for shoot fresh weight in different cultivars show a different trend; however, the highest shoot fresh weight occurs in late cultivar in both N50P0K0 and N50P0K50 treatments. Results also show that maximum yield in early and intermediate cultivars in N50P0K25 treatment and in treatment with phosphorus (N50P25K50) could be observed in the late cultivar. The highest amount of soluble solids in early cultivar and N50P0K25 treatment belong to 12.9 Brixo. In general, though the use of NPK nutrients is effective in most studied traits, the role of N and K in improving the vegetative and reproductive traits in blackberry has been especially tangible for the two early and intermediate cultivars.