Establishment of the Causal Agent(s) of Spike Shedding and Stem Wilting of Pepper (Piper nigrum L.) in Morogoro District, Tanzania

Table 1

Chemical and physical properties of soil (0–20 cm depth) in Tandai village.

Soil property	Optimum value	Nyange hamlet	Doga hamlet	Tandai hamlet	Lukenge hamlet
Chemical properties
pH	4.75–6.25	5.15^STA	5.90^MA	5.60^MA	6.23^SLA
OC	2.0–7.5%	3.03^OP	2.13^OP	2.15^OP	2.23^OP
Tot. N	0.2–0.5%	0.23^M	0.22^M	0.17^L	0.19^L
Bray P	12–96 ppm	10.45^L	10.16^L	12.49^OP	11.323^L
Exch. K^+	91–286 ppm	0.18^D	0.20^D	0.80^D	0.82^D
Exch. Ca^2+	61–139 ppm	1.03^D	0.37^D	0.20^D	0.70^D
Exch. Mg^2+	40–194 ppm	2.35^D	0.97^D	1.04^D	1.30^D
DTPA Fe	12–65 ppm	124.50^H	83.85^H	25.41^OP	38.11^OP
DTPA Mn	5–35 ppm	11.80^OP	62.27^H	32.56^OP	56.57^H
DTPA Zn	2.1–7.0 ppm	7.92^OP	4.33^OP	2.03^L	3.13 ^OP
DTPA Cu	0.51–7.7 ppm	0.0281^D	1.5712^OP	2.3427^OP	3.1143^OP
Physical properties
Soil particle size density (P.S.D)	% Clay	30.2	39.2	37.2	39.22
	% Silt	6.82	10.82	9.82	9.82
	% Sand	62.96	49.96	52.96	50.96
	Texture class	Sandy clay loam	Sandy clay	Sandy clay	Sandy clay

Soil pH: 5.0–5.5, strongly acidic (STA); 5.5–6.0, moderately acidic (MA); 6.0–6.5, slightly acidic (SLA) [38]. Soil N: 0.1–0.2, low (L); 0.2–0.5, medium (M) [38]. Other nutrient elements: L, low; H, high; D, deficient; OP, optimum [39]. USDA texture interpretation manual, textural class triangle.