Table 1.

Overview of genotypes, growth as well as sampling conditions from which exudate samples were collected

Growth matrix	Species	Genotype	Plant age at exudation sampling Days after seeding	Sampling volume (L)	Sampling period (h)	Nr samples per growth matrix
High P Humic Haplic Andosol, pHH2O 5.11, fertilized N:P:K at 150:150:150 mg kg−1	Oryza sativa	Nerica 4, DJ 123, Mudgo, IR 64	38	0.1	3	20
Low P Humic Haplic Andosol, pHH2O 5.11, fertilized N:P:K at 150:10:150 mg kg−1	O. sativa	Mudgo, IR 64	38	0.1	3	10
Hydroponic - half-strength Hoagland	Zea mays	WT 3, rth3 3	22	0.5	2	11
Hydroponic - half-strength Hoagland	Hordeum vulgare	B13 Balashere, Bere JIC 4843	31	0.12	3	9
Hydroponic - half-strength Hoagland (-Zn)	H. vulgare	Bere JIC 4843	31	0.12	3	5d
Hydroponic - half-strength Hoagland (-Fe)	H. vulgare	Bere JIC 4843	31	0.12	3	5d
Quartz sand loam mix1	Z. mays	WT 3, rth3 3	22	0.5	2	12
Loam1	Z. mays	WT 3, rth3 3	22	0.5	2	28
Experimental blanks2						12
Total sum of samples						112

¹substrate characteristics published in Vetterlein et al. (2021)

²MWQ water plus Micropur (10 mg L⁻¹) from different experiments

³see also Vetterlein et al. (2021); Wen and Schnable (1994)

⁴samples were excluded from regression