Suitable row spacing for mechanized cultivation of eggplant in solar greenhouse

The petiole angle first decreased and then increased, reaching its lowest point in treatment T2, while the canopy transmittance of direct solar radiation gradually increased. The yield was positively correlated with the indexes other than the leaf angle, and the dry matter accumulation was highly correlated with the yield. Compared with CK, at 90 days after transplanting (during the peak fruiting period), the chlorophyll a content in eggplant leaves increased by 19.2%, 24.9%, 27.9%, and 17.2% in treatments T1 through T4, respectively.

Chlorophyll b content rose by 14.4%, 15.8%, 27.0%, and 0.9%. Net photosynthetic rate improved by 4.7%, 15.5%, 17.0%, and 5.6%, while dry matter accumulation increased by 1.9%, 4.9%, 4.9%, and 2.9%. Yield enhancements were 0.4%, 6.1%, 11.3%, and 10.9% for T1 to T4, respectively.

Across all these metrics, treatment T3 exhibited the highest values. In addition, the walkway between the borders under this treatment is wider, which is convenient for agricultural machinery operation. Compared with the CK, the T3 treatment is not only conducive to the realization of suitable mechanized cultivation of eggplant in a solar greenhouse, but also can promote the yield increase of eggplant.

Under the conditions of this experiment, T3 emerged as the optimal row spacing arrangement.