Zeolite and Inorganic Nitrogen Fertilization Effects on Performance, Lint Yield, and Fiber Quality of Cotton Cultivated in the Mediterranean Region

GENETIC STUDIES ON YIELD, YIELD COMPONENTS AND FIBER PROPERTIES IN SEGREGATING GENERATIONS OF AN INTRASPECIFIC COTTON CROSS

Chemicals may be used to reduce plant size in cotton (Gossypium barbadense L.), which can increase cotton yield by allowing an increased number of plants per unit area. Foliar sprays of growth retardants Cycocel and Alar were applied at concentrations of 250, 500, and 750 ppm 105 days after planting (square and boll setting stage) to Egyptian cotton cultivar Giza 75 planted at three plant densities (166,000, 222,000, and 333,000 plant ha−1). The objectives of this two-year study were to determine if growth retardants may be substituted for plant density, and vice versa, and to investigate their effects on yield and fiber properties. Number of opened bolls plant−1, seed-cotton yield plant−1, and earliness increased as plant density decreased in both years, as did seed-cotton and lint yield ha−1 in the second season. In the first year, the intermediate plant density gave the highest yields. Plant density had no significant effect on lint percentage or fiber properties. Both Cycocel and Alar increased the number of opened bolls plant−1, boll weight, seed and lint indices, seed-cotton yield plant−1, and both seed-cotton and lint yield ha−1, but effects were not always significant and response varied for different traits. Neither Cycocel nor Alar affected lint percentage, yield earliness, or fiber properties at any plant density. The interaction of plant density × growth retardant was significant for the number of opened bolls m−2 and plant−1, seed-cotton yield plant−1 and ha−1, and for lint yield ha−1. The lowest plant densities, combined with application of Cycocel or Alar, gave the highest number of opened bolls m−2 and plant−1, seed-cotton yield plant−1 and ha−1, and lint yield ha−1. This implied that the effect of growth retardants on cotton yield depended essentially on the number of plants per unit area or space available to each plant and that applying growth retardants could enhance the effect of low plant density.

When alien DNA inserts into the cotton genome in a multicopy manner, several quantitative trait loci (QTLs) in the cotton genome are disrupted; these are called dQTL in this study. A transgenic mutant line is near-isogenic to its recipient, which is divergent for the dQTL from the remaining QTLs. Therefore, a set of data from a transgenic QTL line mutated by Agrobacterium-mediated transformation (30074), its recipient and their F1 hybrids, and three elite lines were analyzed under a modified additive-dominance model with genotype × environment interactions in three different environments to separate the genetic effects due to dQTL from whole-genome effects. Our result showed that dQTL had significant additive effects on lint percentage, boll weight, and boll number per square meter, while it had little genetic association with fiber traits, seed cotton yield, and lint yield. The dQTL in 30074 significantly increased lint percentage and boll number, while significantly decreasing boll weight, having little effect on fibre traits, while those from the recipient and three elite lines showed significant genetic effects on lint percentage. In addition, the remaining QTL other than dQTL had significant additive effects on seed cotton yield, fruiting branch number, uniformity index, micronaire, and short fibre index, and significant dominance effects on seed cotton yield, lint yield, and boll number per square meter. The additive and dominance effects under homozygous and heterozygous conditions for each line are also predicted in this study.

Genetic progress in seed and fiber quality traits of cotton in Argentina

The main objective of the present investigation is to obtain wide genetic variation by using lee it tester analysis involving two seeded testers as male parents, namely, AugUraliall and Karashnelry and four Egyptian cotton culbvars as females (lines) namely Gza80, Giza85, Gza90 and Gia87 (G.barbadense). Eight Ft's, the two tester varieties and the four lone cultivars were grown in a randomized complete block design with three replications in 2006 season to evaluate combining abilities and nature of gene action. Genotypes mean squares were highly significant for all traits except for int percentage (L %), lint index (LI) and uniformity index (U.I). Parents mean squares revealed highly significant differences for all studied traits except for lint percentage (L %) and ant index (U). Higher estimates of dominance (02d) variance than additive valance (02A) were recorded and low narrow sense heritability values (h%n.$) and low magnitude of the ratio Q2gCa/Q25ca (less than unity) were found for first fruaing node (FFN), seed cotton yield (KY), lint yield (LY), lint percentage (1%), seed index (SI), lint index (U), micronalr value (Nie), plessly index (PI) and Upper half mean (U.H.M). On the other hand days of first flower (DFF), boll weight (8W) and uniformity index (U.I) recorded lion estimates of additNe variance (02A) and narrow sense heritability (h%n.$). For the testers, Australian and Karashneky varieties were good combiners for first fruiting node (FFN), days of first flower (OFF), seed cotton yield (SCY), lint yield (LY) and uniformity index (VI). Among female parents the variety Giza85 was the best combiner for days of fist flower (OFF), seed cotton yield (SCY), lint yield (LY), seed index (SI) and uniformity index (MI). Giza87 was the best general combiners for fiber traits. Gza90 was the best general combiner for boa weight (avo, seed index (SI) and uniformity index (U.I). Gza80 was the best combiner for first fruiting node (FIN), days of first flower (OFF), boll weight (BW), seed talon yield (SCY), ant yield (LY), micron* value (Mic) and con* index (F1). It oduld be concluded that (tie hybrid (Australian it Giza85) and (Karashneky it Gza85) may be used for the improvement of seed cotton yield (SCY), lint yield (LT), seed Index (SI) and Upper half mean (URA), while (Australian it Gza80) and (Karashneky x Gza80) hybrids were the best for the Improvement of seed cotton yield (SCY), lint yield (1Y) and pressty Index (PI).

Zero tillage straw retained with optimum N is an important strategy to increase soil fertility and cotton (Gossypium hirsutum L.) yield in wheat (Triticum aestivum L.)-cotton system. A 3 years field experiment was conducted during 2014, 2015 and 2016 to study the impact of two tillage techniques [zero tillage plus wheat straw retained- ZTsr and conventional tillage-CT straw burnt (CTsb, with disc plow, tiller, rotavator, and leveling operations)] and four nitrogen rates namely 0, 100, 150 and 200 kg N ha-1 on cotton yield and soil fertility. Results indicated that bolls/plant–1, weight per boll, seed cotton yields, lint percentage and N recovery efficiency were highest with 150 kg N ha–1. Interaction tillage into N indicated that ZTsr had graeter bolls plant-1, bolls weight, seed cotton yields, lint percentage and N recovery efficiency compared to CTsb. ZTsr had more soil organic matter (SOM) and total soil nitrogen (TSN) compared to CTsb. ZTsr with 150 kg nitrogen per hectare enhanced cotton yield and soil fertility on sustainable basis in arid environment of Dera Ismail Khan.

Foliar sprays of (PGR’s) Cycocel and Alar were applied at concentrations of 250, 500, and 750 ppm after 105 days after plantation (square and boll setting stage) to Egyptian cotton cultivar planted at three plant densities (166.000, 222.000, and 333.000 plant ha−1). Number of opened bolls plant−1, seed-cotton yield plant−1, and earliness increased as plant density decreased in both years, as did seed-cotton and lint yield ha−1 in the second season. In the first year, the intermediate plant density gave highest yields. Plant density had no significant effect on lint percentage or fiber properties. Both Cycocel and Alar increased the number of opened bolls plant−1, boll weight, seed and lint indices, seed-cotton yield plant−1 and both seed-cotton and lint yield ha−1, but effects were not always significant and response varied for different traits. Neither Cycocel nor Alar affected lint percentage, yield earliness or fiber properties at any plant density.

Manipulation of dry matter accumulation and partitioning with plant density in relation to yield stability of cotton under intensive management

Genetic progress in cotton lint and yield components in Argentina

Optimal planting density and sowing date can improve cotton yield by maintaining reproductive organ biomass and enhancing potassium uptake

Adopting a high-density planting system in cotton cultivation has resulted in increased yields compared to traditional methods. Despite the clear benefits, farmers face various challenges throughout the cultivation process, from sowing to harvesting. However, selecting appropriate plant spacings, fertilizer levels and implementing tailored cultivation techniques can significantly enhance productivity. A field experiment was conducted at Siddapur research farm, Regional Agricultural Research Station, Warangal, Telangana, India during kharif 2023 to investigate the “Impact of different plant densities and fertilizer levels on yield attributes, yield and fibre quality characters of cotton in high density planting system (HDPS)”. The experiment was laid out in randomized block design (factorial) and replicated thrice, consisting of 12 treatment combinations comprising of three plant spacings S1: 80 x 20 cm (62,500 plants ha-1), S2: 90 x 15 cm (74,074 plants ha-1), S3: 90 x 60 cm in factor I and four fertilizer levels (F1: 100%RDF, F2: 125%RDF, F3: 100%RDF + Microbial consortia, F4: Control) in factor II. Both the factors significantly influenced the number of bolls per plant, number of bolls m-2 and seed cotton yield per hectare. The results revealed that higher no. of bolls plant-1 were recorded in 90 x 60 cm (18,518 plants ha-1) however, higher no. of bolls m-2, seed cotton yield (2233 kgha-1) obtained from higher plant density (74,074 plants ha-1) with the spacing 90 x 15 cm. Boll weight was not significantly influenced by varied plant spacings and fertilizer levels. Among the different levels of fertilizer, 125%RDF recorded highest no. of bolls per plant, no. of bolls m-2 and seed cotton yield (2362 kgha-1). Fibre quality characters viz., Upper half mean length(mm), micronaire(µginch-1), tenacity(gtex-1) and uniformity index (%) were not significantly influenced by both plant spacings and fertilizer levels as they are primarily governed by genetic makeup of cotton genotypes. For optimum seed cotton yield, cotton should be sown at closer spacing 90 x 15 cm and the application of 125%RDF was economically feasible in high density planting system.

Due to the changing climate, frequent episodes of drought have threatened cotton lint yield by offsetting their physiological and biochemical functioning. An efficient use of irrigation water can help to produce more crops per drop in cotton production systems. We assume that an optimal drip irrigation with low mepiquat chloride application could increase water productivity (WP) and maintain lint yields by enhancing leaf functional characteristics. A 2-year field experiment determines the response of irrigation regimes (600 (W1), 540 (W2), 480 (W3), 420 (W4) 360 (W5) m3 ha−1) on cotton growth, photosynthesis, fiber quality, biomass accumulation and yield. Mepiquat chloride was sprayed in different concentration at various growth phases (see material section). Result showed that W1 increased leaf area index (LAI) by 5.3–36.0%, net photosynthetic rate (Pn) by 3.4–23.2%, chlorophyll content (Chl) by 1.3–12.0% than other treatments. Improvements in these attributes led to higher lint yield. However, no differences were observed between W1 and W2 in terms of lint and seed cotton yield, but W2 increased WP by 3.7% in both years. Compared with other counterparts, W2 had the largest LAI (4.3–32.1%) at the full boll stage and prolonged reproductive organ biomass (ROB) accumulation by 30–35 d during the fast accumulation period (FAP). LAI, the average (VT) and maximum (VM) biomass accumulation rates of ROB were positively correlated with lint yield. In conclusion, the drip irrigation level of 540–600 m3 ha−1 with reduced MC application is a good strategy to achieve higher WP and lint yield by improving leaf photosynthetic traits and more reproductive organ biomass accumulation.

The objective of this study was to determine the effect of sowing dates on cotton yield, its components and fiber quality characters and select the favorable variety for delaying sowing. Cotton growers face a problem of law cotton yield in late sowing (after clover or wheat) at Egypt. The present study was carried out to evaluate six varieties G. 86 , G.94 , G.95 , G.97 , G.92 and G.96 under normal and late sowing dates viz 15th April and 15th May during 2018 and 2019 at Sakha Agriculture Research Station in a randomized complete block design with four replications to study seed cotton yield , lint yield , boll weight , lint percentage, seed index , lint index , fiber length , length uniformity ratio , fiber strength and micronaire reading. All characters showed significant mean squares for varieties in normal and late combined analysis, except fiber strength and micronaire reading and in the combined analysis for normal and late sowing dates. Mean squares for sowing dates were significant for all characters, except fiber length and length uniformity ratio. The main cause of reduction in cotton yield due to that all the Egyptian cotton varieties were needed to grow under full season conditions. It is concluded that varieties G. 97 , G. 95 and G. 94 are response to late sowing date also, G. 96 is somewhat response tolerant but, it had few seed cotton yield to both sowing dates. Fiber quality characters over few affected by late sowing date. Varieties Giza 97, Giza 95 and Giza 94 are average stable and favorable to late sowing date for seed cotton yield according to (Eberhart and Russiell) and GGE- Biplot analyses.

BackgroundToday, stress moderators are employed to mitigate crop loss due to the adverse effects of environmental stress. The current research aimed to investigate the impacts of time and stress moderator types on agro-physiological responses of cotton on conventional and double-cropping systems during 2017 and 2018 under saline conditions. A split-plot factorial experiment was carried out in a randomized complete block design with three replications. Cultivation system [conventional (recommended planting date) and double-cropping systems (sowing after harvest of wheat)] were considered as the main plots, and stress moderator type at four levels [water control, 2 mmol·L–1 Salicylic acid (SA), 100 mmol·L–1 Glycine betaine (GB), and 100 μmol·L–1 sodium nitroprusside (SNP)] and application time (flowering and flowering + bolling stages) were regarded as subplots.ResultsPlant height, reproductive branch number, the number of bolls, 10-boll weight, 1 000-seed weight, biological yield, seed cotton yield, lint yield, chlorophyll a, chlorophyll b, carotenoids, total chlorophyll, sodium, potassium, and proline content were less in double-cropping system comparing with conventional system. Spraying with the stress moderators alleviated soil salinity effects on yield, yield components, and biochemical traits of cotton. SNP spraying led to maximum plant height, branch number, the number of bolls per plant, 10-boll weight and seed cotton yield. SA spraying yielded the highest 1 000-seed weight, biological yield, lint percentage and lint yield. The highest chlorophyll a, chlorophyll b, carotenoids, and total chlorophyll content resulted from SNP spraying. Yield, yield components, and biochemical traits did not respond to the stress moderator types in double-cropping system. However, the highest chlorophyll a, carotenoids, proline content, the number of bolls per plant, and seed cotton yield resulted from SNP spraying in conventional system. No statistically significant differences were observed between spraying with SNP and SA in most studied traits.ConclusionsThe results suggest that the optimum cotton planting time and SNP spraying could be recommended for producing the most suitable yield under saline conditions.HighlightsExternal application of stress modulators increases salinity stress tolerance.Spraying with sodium nitroprusside has more moderating effect.Agro-physiological response of cotton to moderators is stronger in early sowing.Maximum seed cotton yield was achieved at early sowing and spraying sodium nitroprusside.Delayed cultivation reduces cotton yield.

We aimed to investigate the effects of some seed priming and foliar applications on stress prevention in cotton under deficit irrigation conditions. Seed priming with mepiquat chloride (PIX) and foliar applications of salicylic acid (SA) and proline (PRO) were tested at three levels of irrigation at 25, 50, and 100% of field capacity. Plant height, boll number, fiber length and fiber strength were significantly affected by the interaction of irrigation level × treatment. The effects of irrigation level and treatment were significant for boll weight, seed index, seed cotton yield and lint yield. When deficit irrigation conditions (25%) were compared with full irrigation, plant height decreased by 21.6 %, boll number by 18.1 %, boll weight by 26.0%, seed index by 5.8%, seed cotton yield by 25.6% and lint yield by 24.6%. Seed priming with PIX and foliar application of PRO produced significantly higher seed cotton and lint yields, whereas SA application had favourable fiber quality parameters under deficit irrigation conditions. PRO slightly increased fiber fineness. Foliar application of SA positively affected chlorophyll content (SPAD) and leaf area index (LAI) under deficit irrigation. In conclusion, it was recommended that all three practices could be successfully used to alleviate negative impacts under deficit irrigation conditions.