Background

The implementation of hybrid Bt cotton unique to India has been heralded as a grand success by government agencies, seed companies and other proponents, and yet yields have stagnated at low levels and production costs have risen 2.5–3-fold. The low-yield hybrid cotton system of India contributes thousands of farmer suicides to the annual national toll. Conceptual and methodological barriers have hindered bioeconomic analysis of the ecological and social sustainability of such cross-scale agro-ecological problems in time and geographic space, under global technology and climate change. As a paradigm shift, we use conceptually simple, parameter-sparse, theoretically based, mechanistic, weather-driven physiologically based demographic models (PBDMs) to deconstruct the bio-economics of the Indian cotton system.

Results

Our analysis of Indian hybrid cotton system explains some extant ecological and economic problems, and suggests a viable solution. Specifically, the model accurately captured the age-stage mass dynamics of rainfed and irrigated cotton growth/development and the interactions with the key pest pink bollworm across five south-central Indian states, and enabled identification of proximate bioeconomic factors responsible for low yield and their relationship to farmer suicides. The results are reinforced by analysis of Ministry of Agriculture annual state-level data. We explain why short-season, high-density non-GM cotton is a highly viable solution for Indian cotton farmers in rainfed and irrigated cotton areas of the five states, and possibly nationally. The transition from a theoretical bioeconomic construct to a real-world regional bioeconomic analysis proved seamless.

Conclusions

The hybrid long-season Bt technology for rainfed and irrigated cotton is unique to India, and is a value capture mechanism. This technology is suboptimal leading to stagnant yields, high input costs, increased insecticide use, and low farmer incomes that increase economic distress that is a proximate cause of cotton farmer suicides. The current GM Bt technology adds costs in rainfed cotton without commensurate increases in yield. Non-GM pure-line high-density short-season varieties could double rainfed cotton yield, reduce costs, decrease insecticide use, and help ameliorate suicides. The GM hybrid technology is inappropriate for incorporation in short-season high-density varieties.

中文翻译：

---

印度杂交Bt棉与农民自杀的生物经济学

背景

政府机构，种子公司和其他支持者宣称，印度独特的杂交Bt棉的实施取得了巨大成功，但单产停滞不前，生产成本上升了2.5到3倍。印度的低产杂交棉系统为每年的全国死亡人数造成了成千上万的农民自杀。在全球技术和气候变化的背景下，概念和方法上的障碍阻碍了在时间和地理空间上对此类跨尺度农业生态问题的生态和社会可持续性进行生物经济分析。作为范式转换，我们使用概念上简单，参数稀疏，基于理论的机制，基于天气的机械机制，基于生理的人口统计学模型（PBDM）来解构印度棉花系统的生物经济学。

结果

我们对印度杂交棉系统的分析解释了一些现存的生态和经济问题，并提出了可行的解决方案。具体而言，该模型准确地捕获了印度中南部五个州的雨养和灌溉棉花生长/发育的阶段质量动态以及与主要害虫粉红色棉铃虫的相互作用，并能够识别造成低产的主要生物经济因素及其与农民自杀的关系。通过对农业部年度国家级数据的分析，结果得到了加强。我们解释了为什么对于五个州（甚至可能在全国范围内）的雨养和灌溉棉花地区的印度棉农来说，短季节，高密度非转基因棉花是一种高度可行的解决方案。

结论

雨养棉和灌溉棉的长期混合Bt技术是印度独有的，是一种价值获取机制。该技术欠佳，导致产量停滞，投入成本高，杀虫剂使用量增加以及农民收入低下，这加剧了经济危机，这是棉花农民自杀的直接原因。当前的转基因Bt技术增加了雨养棉花的成本，而产量却没有相应增加。非转基因纯系高密度短季节品种可以使雨养棉花产量提高一倍，降低成本，减少杀虫剂的使用，并有助于改善自杀状况。GM混合技术不适用于短季节的高密度品种。