Paradiso Roberta, Di Mola Ida, Ottaiano Lucia, Cozzolino Eugenio, Pelosi Maria Eleonora, Rippa Massimo, Mormile Pasquale, Mori Mauro
Department of Agricultural Sciences, University of Naples Federico II, 80055 Portici, Italy.
Research Center for Cereal and Industrial Crops, Council for Agricultural Research and Economics (CREA), 81100 Caserta, Italy.
Plants (Basel). 2024 Feb 2;13(3):440. doi: 10.3390/plants13030440.
Fruit yield and quality of greenhouse tomatoes are strongly influenced by light conditions and nitrogen (N) availability, however, the interaction between these factors is still unclear. We evaluated the effects on cherry tomatoes of two tunnel plastic covers with different optical properties and three N doses, also in combination with a biostimulant treatment. We compared a diffuse light film (Film1) and a conventional clear film (Film2), and three N levels, corresponding to 50% (N50), 75% (N75) and 100% (N100) of the optimal dose, with and without a microbial plus a protein hydrolysed biostimulant, compared to a non-treated control. The three experimental treatments significantly interacted on several yield and quality parameters. In control plants (untreated with biostimulants), the early yield was higher at reduced N doses compared to N100, with greater increments under the diffusive Film1 compared to the clear Film2 (+57.7% and +37.0% vs. +31.7% and +16.0%, in N50 and N75 respectively). Film1 boosted the total fruit production at all the N rates and with or without biostimulants, compared to Film2, with stronger effects under sub-optimal N (+29.4% in N50, +21.2% in N75, and +7.8% in N100, in plants untreated with biostimulant). Total yield decreased with decreasing N levels, while it always increased with the application of biostimulants, which counterbalanced the detrimental effects of N shortage. Quality traits were mainly affected by the cover film and the biostimulant treatment. The diffusive film increased the content of carotenoids, lycopene and total phenols compared to the clear one, and the biostimulants increased texture, soluble solids, phenols and ascorbic acid compared to the untreated control. It is worth noting that in plants fertilized at 75% of the reference N dose, the biostimulants determined higher yield than the N100 untreated control, under both the covers (+48% in Film1 and +20% in Film2). In conclusion, the diffusive film improved the fruit yield and quality of greenhouse tomatoes in the spring-summer period, presumably avoiding plant stress due to high-intensity direct light. Reduced N rates limited the plant productivity, however, the biostimulant application was effective in compensating for the detrimental effects of sub-optimal supply of N synthetic fertilizers.
温室番茄的果实产量和品质受光照条件和氮（N）有效性的强烈影响，然而，这些因素之间的相互作用仍不明确。我们评估了两种具有不同光学特性的棚膜以及三种氮用量对樱桃番茄的影响，同时还结合了一种生物刺激素处理。我们比较了一种漫射光膜（膜1）和一种传统的透明膜（膜2），以及三种氮水平，分别对应最佳用量的50%（N50）、75%（N75）和100%（N100），有或没有微生物加蛋白质水解生物刺激素的情况，并与未处理的对照进行比较。这三种实验处理在几个产量和品质参数上有显著的相互作用。在对照植株（未用生物刺激素处理）中，与N100相比，较低氮用量下的早期产量更高，与透明的膜2相比，在漫射的膜1下增加幅度更大（N50时分别为+57.7%和+37.0%，N75时分别为+31.7%和+16.0%）。与膜2相比，膜1在所有氮用量水平下，无论有无生物刺激素，都提高了总果实产量，在次优氮水平下效果更强（未用生物刺激素处理的植株中，N50时为+29.4%，N75时为+21.2%，N100时为+7.8%）。总产随氮水平降低而下降，而施用生物刺激素总能增加产量，这抵消了氮短缺的不利影响。品质性状主要受棚膜和生物刺激素处理的影响。与透明膜相比，漫射膜增加了类胡萝卜素、番茄红素和总酚的含量，与未处理的对照相比，生物刺激素增加了果实质地、可溶性固形物、酚类和抗坏血酸的含量。值得注意的是，在按参考氮用量的75%施肥的植株中，在两种棚膜下，生物刺激素处理的产量均高于未处理的N100对照（膜1下为+48%，膜2下为+20%）。总之，漫射膜在春夏季提高了温室番茄的果实产量和品质，可能避免了因高强度直射光造成的植株胁迫。降低氮用量限制了植株生产力，然而，施用生物刺激素有效地补偿了次优供应氮合成肥料的不利影响。
