Twenty-two tomato (Solanum lycopersicum L.) genotypes were examined for correlation and path analysis in the randomized block design under open field conditions. Total fruit yield showed a significant positive correlation with the number of fruits per plant, average fruit weight, lycopene content, and percent seedling survival in the field at both the genotypic and phenotypic levels. A strong correlation between these characters revealed that selection based on these characters would consequently improve the total fruit yield. Path analysis showed that the number of fruits per plant, average fruit weight, percent seedling survival in the nursery, and number of locules per fruit exhibited high positive direct phenotypic effects on total fruit yield, whereas the number of fruits per plant, average fruit weight, percent seedling survival in the field, and pollen viability had very high positive direct genotypic effects. Therefore, to increase the yield, it would be profitable to prioritize these traits in the selection program.
For centuries, stem cuttings harvested from sexually mature trees have been recognized to be more difficult to root than those from juvenile shoots. This has been poorly understood and attributed to a combination of ontogenetic and physiological ageing. The recent suggestion that micro-RNA may play a key role in phase change has stimulated a re-examination of some old data that identified pre-severance light x nutrient interactions affecting the rooting ability of stem cuttings. This was linked to vigorous growth and active photosynthesis without constraint from accumulated starch. Support for the prime importance of physiological factors was also obtained when seeking to induce physiological youth in the crowns of ontogenetically mature trees by the induction of roots within the tree crown. Meanwhile, at the other end of the phase change spectrum, floral initiation occurred when the opposite set of environmental conditions prevailed so that growth was stunted, and carbohydrates accumulated in leaves and stems. A re-examination of this literature suggests that rooting ability is driven at the level of an individual leaf and internode emerging from the terminal bud affecting both morphological and physiological activity. In contrast, flowering occurs when internode elongation and assimilate mobilization were hindered. It is therefore suggested that the concepts of juvenility and ageing are not relevant to vegetative propagation and should instead be replaced by physiological and morphological ‘fitness’ to root.
Low temperature is one of the most significant environmental factors that threaten the survival of subtropical and tropical plant species. By conducting a study, which was arranged in a completely randomized design with three replicates, the relative freezing tolerance (FT) of four Iranian pomegranate cultivars, including ‘Alak Torsh’, ‘Tabestaneh Torsh’, ‘Poost Sefid’, and ‘Poost Syah’, as well as its correlation with some biochemical indices, were investigated. From each cultivar, pieces of one-year-old shoot samples were treated with controlled freezing temperatures (−11, −14, and −17 ℃) to determine lethal temperatures (LT50) based on survival percentage, electrolyte leakage, phenolic leakage, and tetrazolium staining test (TST) methods. Results showed that FT was higher in the second year with a lower minimum temperature and a higher concentration of cryoprotectants. The stronger correlation of electrolyte leakage with survival percentage (r = 0.93***) compared to the other three indices explained that this index could be the most reliable injury index in determining the pomegranate FT to investigate freezing effects. Of all four cultivars, ‘Poost Syah’ was the hardest by presenting a higher FT than ~ −14 ℃ in mid-winter. Accordingly, this pomegranate cultivar seems to be promising to grow in regions with a higher risk of freezing and to be involved in breeding programs to develop novel commercial cultivars.
Among major global threats to papaya cultivation, papaya ringspot virus (PRSV) is the most challenging one. In the absence of any PRSV resistant commercial papaya cultivar, PRSV management is restricted to minimizing yield losses. ICAR-Indian Agricultural Research Institute, Regional Station, Pune has developed PRSV tolerant dioecious papaya lines, Pune Selection (PS)-1, PS-2, PS-3 and PS-5. Being dioecious these lines have limited acceptability among farmers. Gynodioecious population from these lines were developed and characterized. They are numbered PS-1-1, PS-2-1, PS-3-1 and PS-5-1. These lines were characterized against prevailing commercial gynodioecious cultivar, Red Lady, for five generations. The average plant height of PS-2-1 and PS-5-1 (183 cm) was more than Red Lady (158 cm), however, stem girth of all lines was lesser than Red Lady. The fruiting height of all lines was less than Red Lady (87 cm). Length of the fruiting column of all lines was more than Red Lady (37 cm), except in PS-1-1. Fruit yield of all lines was more than Red Lady (16 kg/plant). Intensity of PRSV infection in Red Lady (48%) was considerably more than all lines. These lines can be used for developing PRSV tolerant gynodioecious papaya variety.
Bangladesh’s coastal regions are rich in saline water resources. The majority of these resources are still not being used to their full potential. In the southern Bangladeshi region of Patuakhali, research was conducted to investigate the effects of mulching and drip irrigation on tomato yield, quality, and blossom-end rot (BER) at different soil salinity thresholds. There were four distinct treatments applied: T1= drip irrigation with polythene mulch, T2 = drip irrigation with straw mulch, T3 = drip irrigation without mulch, and T4 = standard procedure. While soil salinity was much greater in treatment T3 (1.19–8.42 dS/m) fallowed by T4 (1.23–8.63 dS/m), T1 treatments had the lowest level of salinity and the highest moisture retention during every development stage of the crops, ranging from 1.28–4.29 dS/m. Treatment T3 exhibited the highest soil salinity levels (ranging from 1.19 to 8.42 dS/m), followed by T4 with a range of 1.23 to 8.63 dS/m. In contrast, T1 treatments consistently maintained the lowest salinity levels (ranging from 1.28 to 4.29 dS/m) and the highest moisture retention throughout all stages of crop development. In terms of yield, drip irrigation with no mulch treatment (T3) provided the lowest output (13.37 t/ha), whereas polyethylene mulching treatment (T1) produced the maximum yield (46.04 t/ha). According to the study, conserving moisture in tomato fields and reducing soil salinity may both be achieved with drip irrigation combined with polythene mulch. The research suggests that employing drip irrigation in conjunction with polythene mulch could effectively preserve moisture in tomato fields and concurrently decrease soil salinity.
Organomineral fertilizer is used to improve and ameliorate the supply of nutrients in soils. Right and adequate application of fertilizers are determinants of its nutrient supply efficiency, which in turn enhances the vegetative growth and yield of cucumber. Field experiments were conducted at the Research Farm of the Federal University of Agriculture, Abeokuta, Nigeria, to assess the effects of variety and rate of organomineral fertilizer on cucumber growth and yield. Trials were conducted from June to August 2019 and repeated from September to November 2019. The cultivars were Poinsett, Greengo, and Monalisa. The rates of organomineral fertilizer were 0, 2.5, or 5.0 tons. ha−1. The treatments were replicated three times. Cucumber vegetative characters, yield, and yield components were studied. ‘Greengo’ produced the most leaves, followed by ‘Monalisa’; ‘Poinsett’ produced the least. Application of 5.0 tons. ha−1 organomineral fertilizer produced the longest vines and fruits. ‘Greengo’ had the earliest days to 50% flowering, followed by ‘Monalisa’; ‘Poinsett’ had the most days to 50% flowering. Plants treated with an application of 5.0 tons. ha−1 organomineral fertilizer attained 50% flowering in 29 days, but in 30 days with an application of 2.5 tons. ha−1 organomineral fertilizer; the control treatment attained 50% flowering in 33 days. Application of 5.0 tons. ha−1 organomineral fertilizer produced the longest fruits, thicker fruit diameter, and highest fruit yield compared with 2.5 and 0 tons. ha−1 of organomineral fertilizer treatments. The Greengo variety with application of 5.0 tons. ha−1 of organomineral fertilizer is recommended for optimum growth and yield in south western Nigeria.
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