Waterlogging In Cotton: Stress, Consequences, Adaptability, Mechanisms and Measures for Mitigation of Yield Losses

From many years, global cotton production suffers from waterlogging stress. Climatic variation and heavy rainfall conditions with poor internal soil drainage mechanism limits the growth and development of cotton crop due to waterlogging. It reduced the soil oxygen which causes the severe yield losses and sometimes even failure of a crop. Indeterminate growth habit of cotton plant makes it able to adapt this stress by activation of the escape, self compensation and quiescence mechanism. The reduction of biomass, development of adventitious roots and accelerated growth mechanism, all are associated with adaption and tolerance mechanisms. Waterlogging significantly affect the cellulose and sucrose content of fiber in cotton. Sodic soils also exacerbate the waterlogging stress because these soils already suffer by aeration stress. Different growth stages are effect differently but flowering and boll setting stage is more sensitive to waterlogging conditions.

Plant arrangement in soybean crops with indeterminate growth in brazilian Cerrado

The suitability of the spatial arrangement of soybean is a tool capable of promoting better use of the agricultural environment, allowing the crop to express its yield potential. Therefore, the aim of this study was to evaluate different implementation systems with and without an increase in the plant population of soybean with indeterminate growth habit variety cultivated in the Brazilian Cerrado. The experiments were performed in the 2013/14 and 2014/15 seasons in Rio Verde, Goias state. The experimental design was randomized blocks with four replication in a 4x2 factorial scheme. The treatments presents four implementation systems (traditional, reduced, double rows and crossed) associated with two populations of BMX Potência RR® (recommended and increased by 33%) with presented indeterminate growth habit. The results indicate that the reduced system has an adoption potential for soybean with indeterminate growth habit. The increase in the plant population in the 2013/2014 season, increased 20% of soybean yield in relation to the recommended population, proving to be a promising technique since it considerate the costs involved.

INDUSTRIAL TOMATO FOR FRESH CONSUMPTION: A TECHNICAL AND ECONOMICALLY VIABLE ALTERNATIVE

The cultivation of hybrid tomatoes, intended for fresh consumption, with a determined growth habit, and without support, is an alternative that has a lower production cost. The research aimed to evaluate the productivity and economic viability of different tomato genotypes, with a determinate and indeterminate growth habit. The experimental design was in completely randomized blocks. Ten hybrids and a variety were grown in 2016, and nine hybrids, and a variety in 2018, with a spacing of 0.5 meters between plants. Harvests were carried out in four periods in 2016, at 72, 82, 97, and 105 days after transplanting (DAT); and in 2018 at 81, 87, 97, and 111 DAT. After harvesting, the gross value of production and profit were quantified. The hybrids that obtained the highest production per plant in 2016 were Gabrielle (6,010 kg), with support; Thaise (5.529 kg); and N901 (5.003 kg). In 2018, Dominador and Thaise hybrids had the highest production, with 4.109 and 3.961 kg per plant, respectively. The gross value of tomato production in 2016 was higher than in 2018 for all hybrids and variety, except for Dominador hybrid. Hybrids with a determined growth habit and conducted without support are a profitable alternative to produce tomatoes intended for fresh consumption, especially the hybrid Gabrielle, which had the highest production. The economic viability of hybrids grown without support is superior to all hybrids with support.

Location of Helicoverpa zea (Lepidoptera: Noctuidae) larvae on different plant parts of determinate and indeterminate soybean

Helicoverpa zea (Boddie) is a damaging pest of many crops including soybean, Glycine max (L.), especially in the southern United States. Previous studies have concluded that oviposition and development of H. zea larvae mirror the phenology of soybean, with oviposition occurring during full bloom, younger larvae developing on blooms and leaves, intermediate aged larvae developing on varying tissue types, and older larvae developing on flowers and pods. In a field trial, we investigated the presence of natural infestations of H. zea larvae by instar in determinate and indeterminate soybean varieties. In complementary experiments, we artificially infested H. zea and allowed them to oviposit on plants within replicated cages (one with a determinate variety and two with an indeterminate variety). Plants were sampled weekly during the time larvae were present. In the natural infestation experiment, most larvae were found on blooms during R3 and were early to middle instars; by R4, most larvae were found on leaves and were middle to late instars. In contrast, in the cage study, most larvae were found on leaves regardless of soybean growth stage or larval stage. Determinate and indeterminate growth habit did not impact larval preference for different soybean tissue types. Our studies suggest H. zea larvae prefer specific tissue types, but also provide evidence that experimental design can influence the results. Finally, our finding of larval preference for leaves contrasts with findings from previous studies.

DEFOLIATION LEVELS AT VEGETATIVE AND REPRODUCTIVE STAGES OF SOYBEAN CULTIVARS WITH DIFFERENT RELATIVE MATURITY GROUPS

ABSTRACT Soybean tolerance to defoliation may be affected by relative maturity group (RMG) of the cultivar. For this reason, this study was carried out to evaluate the effects of artificial defoliation at vegetative and reproductive stages on the agronomic performance of soybean cultivars with different RMG. Two experiments were carried out in greenhouse conditions in Lages, Santa Catarina State, Brazil. Defoliation was carried out at V6 in the first experiment and at R3 in the second experiment. Three cultivars with contrasting RMG were used: BMX Veloz (RMG of 5.0, indeterminate growth habit), NA 5909 (RMG of 5.9, indeterminate growth habit), and TMG 7262 (RMG of 6.2, semi-determinate growth habit). Each cultivar was submitted to five defoliation levels: 0.0, 16.6, 33.3, 50.0, and 66.6%. Leaf expansion after defoliation, grain yield and its components were determined. The BMX Veloz showed lower leaf expansion capacity and lower grain yield when compared to the other cultivars when defoliated at V6. Grain yield of the three cultivars only showed significant decreases with defoliation levels higher than 16.6% at R3. The cultivar BMX Veloz is less tolerant to defoliation during the vegetative stage when compared to the cultivars NA 5909 and TMG 7262. Cultivar maturity group does not interfere with soybean tolerance to defoliation at the reproductive stage in greenhouse conditions.

Tomato production in hydroponic system using different agrofilms as greenhouse cover

ABSTRACT Protected cultivation has increased over the years. More studies on the benefits of using photoselective agrofilms are necessary. The choice of material to cover the greenhouse is a decisive factor for crop development and production. The aim of this study was to evaluate the effect of diffuser and blue-colored agrofilms on the production of different tomato cultivars of indeterminate growth habit under NFT hydroponic system. A completely randomized design in a 2x3 factorial scheme (two environments and three cultivars) was used: two agrofilm types (blue and diffuser) and 3 cultivars (Monterrey, Arendell and Totalle). Each plot consisted of 30 plants per treatment, with four replicates. Commercial tomato seedlings of indeterminate growth habit grafted on rootstock cultivar (Shincheonggang) were used. During the experiment, the electrical conductivity, intensity of radiation inside the greenhouse, gas exchange, soluble solids, lycopene content, pH and fruit production were evaluated. We concluded that the amount of radiation transmitted through the diffuser favors an increase of about 18% in gas exchange, 12% in lycopene content and 9.4% in tomato crop production.

The ecophysiology of cape gooseberry (Physalis peruviana L.) - an Andean fruit crop. A review

In order to review the literature on the ecophysiology of the cape gooseberry, it was found that this typical Andean plant, in Colombia adapts to a wide altitudinal range of the tropical cold climate, that is, between 1,800 and 2,800 meters above sea level (m a.s.l.), with optimal medium temperatures between 13 and 16°C and base (minimum) temperatures for stem and fruit growth are relatively low, 6.3 and 1.9°C, respectively, however it does not withstand temperatures <0°C. Likewise, the Andean conditions of the tropics such as high solar radiation and day lengths <12 hours, rather short, favor the flower initiation. 1,500-2,000 hours year-1 of direct sunshine are the most favorable for the size, quality and ripening of the fruit. Under field conditions in Bogota, a photosynthesis rate of A = 10.545 μmol CO2 m-2 s-1 and light compensation point Ic = 13.645 μmol photons m-2 s-1 was measured. As a plant with an indeterminate growth habit, a constant supply of water is essential, while high amounts or heavy rains after a dry season cause cracking of the fruits, just as the plant does not tolerate waterlogging for more than 4 days. Cape gooseberry is classified as moderately tolerant to salinity and 30 mMol NaCl curiously promote growth, having mechanisms, such as increased antioxidant activity, to protect against saline conditions.

The Estimation of Nitrogen Uptake and Utilization Efficiency in Cotton by the Fertilizer-Response Model

Due to the indeterminate growth habit of cotton crops, a better understanding of N status at the rational fertilizer regime is important to promote lint yield. The fertilizer-response model was employed to evaluate N status by analyzing data of shoot dry mass, N content and N concentration at different growing stages. A field study was conducted on drip-irrigated cotton plants with N fertilizer addition in total amounts of 0 (N0), 120 (N1), 240 (N2), 360 (N3) and 480 (N4) kg ha-1 in Xinjiang, China in 2016. Thirty percent of total fertilizers were applied at planting and the rest 70% were applied over six applications. The N fertilizer treatment at the accumulative rate of 70 kg ha-1 was enough to induce the N status of steady state accumulation 60 days after germination. Since 90 days the treatments that delivered the N amount between 120 and 240 kg ha-1 was deficient for cotton demand, higher rates from 360 and 480 kg ha-1 induced inherent N reserve and resulted in the highest level of yield. With regard to the practical meaning, the N fertilizer dose of 360 kg ha-1 can be used for cotton growth. The N fertilizer dose of 120 kg ha-1 can be recommended when the yield of 5,840 kg ha-1 lint can meet the goal of cotton culture. ********* In press - Online First. Article has been peer reviewed, accepted for publication and published online without pagination. It will receive pagination when the issue will be ready for publishing as a complete number (Volume 47, Issue 4, 2019). The article is searchable and citable by Digital Object Identifier (DOI). DOI link will become active after the article will be included in the complete issue. *********

Molecular tagging of photoperiod responsive flowering in Indian bean [Lablab purpureus (L.) Sweet] Vinita Ramtekey*, Arpit Bhuriya, Dipendra Ayer, Vipulkumar Parekh, Kaushal Modha, Bhushan Kale, Gopal Vadodariya and Ritesh Patel (

Photoperiod responsive flowering and growth habit might have played a key role in domestication of lablab bean (Lablab purpureus) and currently shifting its cultivation from intercropping to monoculture. Most of the landraces of lablab bean exhibit photoperiod sensitivity in flowering and indeterminate growth habit. A cross was made between GNIB21 and GP189 which are phenotypic extremes for photoperiod responsive flowering. The F1 hybrid exhibited dominant traits like indeterminate growth habit and photosensitive flowering endowed from male parent. Segregation pattern of 3:1 in F2 generation indicated monogenic recessive nature of photoperiod insensitive flowering. Bulk segregant analysis in F2 population revealed association of PvTFLy1, a locus governing determinate growth habit in lablab bean, with photoperiod responsive flowering where an amplicon of 300 bp was observed in photo sensitive GP189 while it was absent in photo insensitive variety GNIB21. Significant ÷2 test indicated coupling phase of linkage between PvTFLY1 and photoperiod responsive flowering. Linkage analysis placed PvTFLY1 at the distance of 19.23 cM from the locus governing photoperiod responsive flowering. The linkage between growth habit and photoperiod responsive flowering in common bean, soybean and Indian bean suggest that these traits may be governed by mutation or deletion of E3 (or GmPhyA3) and Dt1 homologs in Indian bean. Information available on characterized genes for photoperiod responsive flowering and determinate growth habit from common bean, soybean and other related legumes may be utilized for isolation, characterization, mapping and molecular dissection of genes involved in regulation of photoperiod responsive flowering in Indian bean.