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Initial population of Meloidogyne javanica (Pi) expressed in number of second stage juveniles (J2) in 100 mL of soil in the experimental area before beginning the experiment.
Source publication
The objective of this work was to quantify damage and yield losses in lettuce parasitized by Meloidogyne javanica, as well as the growth characteristics of naturally cultivated field plants infested by this pathogen. The experimental area consisted of four seedbeds of 10.0x1.60 m cultivated with 160 plants in each, totaling 640 plants. The damages...
Context in source publication
Context 1
... low population of J2/100 mL of soil (16) found before the installation of the experiment was explained by the fact that the soil had been left to fallow for four months (Table 3). Rodrigues et al. (2016) also conducted an experiment in a cultivated area with lettuce in Iúna, Brazil, which remained fallow for six months, and found on average 6.3 J2 of M. javanica/100 mL of soil at the beginning of the experiment. ...Similar publications
The effect of different initial population density of root-knot nematode and damage they cause to the plants (in terms of root-galling) in dragon fruit, and nematode multiplication rate in soil was studied. The initial population density of nematodes (200, 500, 1000 and 2000 J2s/ 200 cm 3 soil) caused significant number of galls on the dragon fruit...
Citations
... Lettuce plants are usually susceptible to root-knot nematodes (Meloidogyne spp.). Depending on the nematode population level in the soil, it can cause losses of U$ 23.19 for the cultivation of 2000 lettuce plants [11]. UAV images can be used to investigate nematode-infested areas, as reported for coffee [12][13][14] and soybeans [15] crops, but not yet used in lettuce crop. ...
Lettuce (Lactuca sativa) is an important horticultural commodity all over the world, and its growth can be affected by root-knot nematodes (Meloidogyne spp.). To keep track of plant behaviors, growers are using new technologies. In this paper, aerial images were obtained using a low-cost unmanned aerial vehicle (UAV) to gather crop information in a short time giving acceptable accuracy for decision-making in the field. Evaluations were done to check the flight height interference in the image's quality for lettuce mapping, and select the best one to estimate the effect of root-knot nematode incidence on lettuce growth. In a field infested with M. incognita, lettuce seedlings were planted in plots treated with bionematicide and control plots. Aerial images were obtained using low-cost UAV in four flight heights performed for five weeks, along with field measurements. Images were processed and used to calculate vegetation indices (VI) and vegetation cover (VC). After lettuce harvesting, nematode eggs were extracted from plants' roots and quantified. Plots treated with bionematicide showed no difference from the control plots in eggs number and lettuce growth. Differences in VI values between the flight heights were not consistent, suggesting that VI values could be affected by the lack of luminosity calibration in each flight condition. VC values calculated from field data presented strong positive correlations with VI and VC values from UAV image data, indicating that RGB images obtained by UAV can be used in the detection of diseases that affect plant growth, as well as following up harvesting time.
