Gas exchange, photosynthetic pigments, and growth in tomato: lettuce intercropping

Abstract

The intercropping system is characterized by interspecific competition and leads to one of the most limiting abiotic factors for high plant yield in this cropping system. Plants under low light can carry significant weight in physiological parameters that can limit growth. Light is one of the abiotic factors that limits productivity; in the present study, it was hypothesized that tomato (Solanum lycopersicum L.) and lettuce (Lactuca sativa L.) intercropping in different transplanting periods promotes changes in gas exchange, photosynthetic pigments, and biomass accumulation in two lettuce cultivars. An experimental study was carried out in Jaboticabal, Sao Paulo, Brazil. The treatments consisted of a combination of the following factors: lettuce (one 'Lucy Brown' plant between two tomato plants and two 'Vanda' plants between tomato plants), two cultivation systems (intercropping and monoculture), and four lettuce transplanting periods (0, 7, 14. and 21 d after tomato transplanting). The experiment was a randomized block with a 3 × 2 × 4 factorial design and four replicates. Transpiration and stomatal conductance were reduced in lettuce by insterspersing plants under a monoculture system. Lettuce-tomato intercropping severely reduced photosynthesis, fluorescence, chlorophyll pigment content, and DM accumulation. Therefore, 'Vanda' is better than 'Lucy Brown' for intercropping with tomato.

Chlorophyll Fluorescence and Fruit Quality Response of Blueberry to Different Mulches

“…Therefore, for T1 in cv. Ochlockonee, with no mulch, an increase in Ts was allowed, stimulating an increase in gs, which could have generated an increase in water demand, as various authors pointed out in their results [58,60,61]. Despite the high variability of gs in response to soil temperature (R 2 = 0.13; Figure 2C, the significance (p < 0.001) showed that the response of gs had a negative tendency to increase the predictor variable (Ts), which validates the statements in the previous paragraph.…”

Intercropping of Eggplant and Tomato as Function of Times of Transplant and Cropping Season

“…According to Andriolo (2000), high air temperatures combined with low levels of radiation are harmful to crops, because they decrease photosynthesis, maintaining high respiration and altering hormonal balance, favoring the etiolation of plants. Cunha-Chiamolera et al (2017) observed that the shading conditions imposed by tomato-lettuce intercropping reduced gas exchange, chlorophyll pigment contents, and growth rate of the secondary crop (lettuce). When lettuce was transplanted later than tomato, the shading of tomato on lettuce plants was higher and caused harmful effects on physiological parameters and dry matter.…”

“…Low temperatures undermine the development of eggplant, being one of the major climatic factors that affect flowering and fruiting (FILGUEIRA, 2013). Temperatures below 14 ºC inhibit growth, flowering and fruiting, and the ideal range for fruit set occurs between 28 and 34 °C (REIS et al, 2007).…”

“…Under low light, the energy processes of plant metabolism will be reduced, such as the synthesis of ATP and carbohydrates, causing less biomass production and decreased yield (GONG et al, 2015). Cunha-Chiamolera et al (2017) observed a 74% reduction in lettuce yield due to the shading caused by tomato plants. These same authors point out that the lettuce plants in monoculture were not restricted by luminosity and achieved higher yield.…”