Protecting floral buds (squares) from insect damage in cotton during early growth is a priority for crop managers despite unclear implications for yield potential and increased system risks from early‐season insecticide use. This study was conducted to determine the compensatory responses of high‐yielding Bacillus thuringiensis (Bt) cotton, Gossypium hirsutum L. cultivars, following manual square damage across 30 experiments, spanning different seasons and environments under commercial production conditions. Square removal from the first five sympodia (fruiting branches) before flowering reduced yield by 9% in one experiment, increased yield by 9%–12% in three experiments and had no effect in the remaining experiments. The most damaging treatment, with squares removed twice across 10 sympodia, reduced yield in just nine experiments by 10%–23%. Lint strength and length remained high, exceeding Australian market preferences. Micronaire decreased with later or more severe square loss particularly in shorter season environments, but economic impact varied. Compensatory growth following pre‐flowering square loss increased fruiting site production without raising total biomass or boll proportion commensurately and caused only minor boll opening delay (<4 days). Yield compensation occurred through increased boll retention at the first position on upper canopy sympodia and more distal positions on remaining sympodia and was un‐reliant on growth of additional mainstem sympodia. Square loss impacts were greater after commencement of flowering or when pre‐flowering losses continued during the early‐flowering period. Crop managers can have confidence to reduce pre‐flowering pesticide use without jeopardizing high yields, which may produce additional systems benefits.

中文翻译：

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早季花芽损失对高产 Bt 棉作物的成熟度、产量和皮棉质量影响不大


在棉花的早期生长过程中保护花芽（方块）免受虫害是作物管理者的首要任务，尽管对产量潜力的影响尚不清楚，并且早期使用杀虫剂会增加系统风险。本研究旨在确定高产苏云金芽孢杆菌 （Bt） 棉花 Gossypium hirsutum L. 栽培品种在 30 个实验中手动方形损伤后的补偿反应，跨越商业生产条件下的不同季节和环境。在开花前从前 5 个交足点（结果枝）中去除正方形，在 1 个实验中使产量降低了 9%，在 3 个实验中提高了 9%–12%，而在其余实验中则没有效果。最具破坏性的处理是在 10 个同足中去除两次方块，仅在 9 个实验中就将产量降低了 10%–23%。皮棉强度和长度仍然很高，超出了澳大利亚市场的偏好。马克隆值随着较晚或更严重的平方损失而减少，尤其是在较短季节的环境中，但经济影响各不相同。花前方形损失后的补偿性生长增加了子点的产量，而没有相应地提高总生物量或棉铃比例，只造成了轻微的棉铃开放延迟（<4 天）。产量补偿是通过增加上冠交足上第一个位置的棉铃保留和剩余交足上更多的远端位置来实现的，并且不依赖于额外的主茎交足的生长。方形损失影响在开花开始后或在开花初期继续时继续。作物管理者可以有信心在不损害高产量的情况下减少开花前农药的使用，这可能会产生额外的系统优势。